I Built a $20K/Month App in 83 Days

0:00 This started as a fun side project, but we turned it into a real business.

0:03 Meet Brian.

0:05 He and his girlfriend built a really simple mobile app,

0:08 and in less than 3 months, they grew it to over $20,000 [music] a month.

0:12 We set a number and didn't start building until we hit it.

0:15 You might think he validated the idea like everyone else, but no.

0:19 He did something I've never seen before,

0:22 and it's called [music] the commitment metric.

0:24 We made sure that people committed to this product

0:26 before writing a single line of code.

0:28 So, I brought Brian onto the channel to break it all down for me.

0:32 In this episode, we'll dive into the amazingly

0:35 simple app that makes over $20,000 a month,

0:38 why you should resist the temptation to build

0:41 anything until you hit this one number,

0:43 and the new framework to validate business ideas in an AI world.

0:48 This one is a great story, so let's dive [music] in.

0:51 I'm Pat Walls, and this is Starter Story.

0:56 All right.

0:56 Welcome Brian to the channel.

0:58 Tell me about who you are, what app you built, and what's your story.

1:01 Hey Pat, nice to meet you.

1:02 My name is Brian Shin, and we built a disposable camera app called Once.

1:06 We launched back in December 2025, [music] and fortunately,

1:09 we were able to hit 20K in monthly revenue within 83 days of launch.

1:13 So, today, I really want to share exactly how we pre-validated Once before

1:18 [music] writing a single line of code,

1:19 and also some of the growth playbooks that we had to grow

1:22 Once from zero all the way to $20,000 in monthly revenue.

1:25 Okay, cool.

1:26 I mean, awesome to have you here.

1:27 Would you be able to just explain what your app does, who uses it,

1:31 and pull up some of your revenue dashboards

1:33 to show that this is legit to the audience?

1:35 Yeah, for sure.

1:35 So, Once is basically a disposable camera for events, especially for weddings,

1:40 birthday parties, and these days even for some corporate events.

1:43 So, anything where a group of people can come together, have fun,

1:46 and capture all the candid moments, Once can play a role there.

1:50 And our pricing is based on the number

1:52 of guests that you want to invite into your event.

1:55 So, if it's like a small birthday party with just 10 people,

1:58 it's going to be just $2.

1:59 But, if it's like a bigger wedding for instance,

2:01 if it's like 150 people, it'll be $50.

2:04 So, that's the more usage, the more guests,

2:06 the more higher tier that you would need

2:08 to purchase in order to use [music] Once.

2:10 So, it's been around 3 months since launching,

2:12 and our weekly active users is around 10,000 to 12,000 users at the moment.

2:17 And in terms of revenue, this month we're totaling around $22,000.

2:21 And this is our internal dashboard calendar where you can see

2:24 all of our active users who have scheduled an event through Once.

2:27 And as you can see, in February, there are around more than 300 events.

2:30 And for March, we got around 700 events coming up real soon.

2:34 Here's what I love about Brian's story.

2:36 It's a great example of someone who focused on growth

2:39 and then hit $20,000 a month in less than 90 days.

2:43 And this got me thinking.

2:44 We talked to dozens of mobile app

2:46 founders every week right here in this channel,

2:48 and I always ask them the same question.

2:50 How did you actually grow your app?

2:52 Well, since we talked to so many people, we decided to turn all of their answers

2:56 into a free guide that you can download right now.

2:59 It's called the mobile app growth cheat sheet,

3:02 and inside you will find the seven different marketing tactics that are

3:05 working for real founders right now making money with mobile apps.

3:09 If you're ready to focus on growth and actually grow your app,

3:13 just head to the first link in the description

3:15 to download the entire guide for free.

3:18 I promise it won't disappoint.

3:20 All right, let's get back to the episode.

3:21 Okay, cool.

3:22 I mean, this looks like a really cool app.

3:24 I can see why it's popular and why it's growing.

3:26 I want to understand a little bit about your background.

3:28 How did you get to this point where you're building this cool consumer

3:31 app that over 300 people are about to use this month at events?

3:34 What's your background?

3:36 So, before founding Once, I co-founded a venture-backed B2B startup.

3:40 It's completely different from Once.

3:42 It was more of a heavy sales-driven 50-person company.

3:45 So, building this venture-backed startup really showed me what a real

3:48 business is and everything related to building a fast-growth company.

3:51 And while I was at the company,

3:52 I found the whole bootstrap scene, which I didn't know existed before.

3:56 I met all these really cool indie hackers and bootstrap

3:58 founders who are validating in a very small way,

4:02 so that it's rather a safer, smaller bet,

4:04 as opposed to betting your whole life on something that's bigger.

4:07 And I don't think there's right or wrong here,

4:09 but I really wanted to try this new path of building a bootstrap company.

4:13 And that's why this time I really wanted

4:15 full control over the product that we built.

4:17 Hence me and my co-founder, my girlfriend,

4:20 we decided to go fully bootstrap this time.

4:23 Okay, cool.

4:23 Let's switch topics a little bit and talk about the idea.

4:25 So, how do you actually find the idea

4:27 for this app that eventually makes over $20,000 a month?

4:30 The whole story comes from me and my co-founder, who is my girlfriend.

4:33 Just last year we traveled to almost seven, eight different countries,

4:37 and every single city we go to, we bring around a disposable camera.

4:41 If you try using a disposable camera, it's [music] such a simple product,

4:44 but it's so magical in a way that it has so many limitations.

4:48 You can't see the photo right away.

4:50 You have a limited amount of shots, but I think those limitations,

4:53 it actually makes the whole experience much real.

4:55 So, really the whole idea behind Once was,

4:58 why don't we try to build [music] a digital

5:00 experience that almost replicates that traditional disposable camera,

5:04 was the whole idea behind it.

5:05 That's awesome.

5:06 Let's talk about how you built this app.

5:08 How long did it take to build this app, and what was that journey like?

5:12 So, the first version took around a week or two.

5:14 It was a web app that kind of just had

5:16 the core features of what a mobile app intended to have.

5:19 We had a Halloween party hosted by my friend coming up,

5:22 so we built out this web version.

5:23 We printed out some invitation codes,

5:25 so that everyone in the party can join in, take photos.

5:28 And honestly, it broke many times during the event,

5:31 but we were able to validate the core

5:33 idea that people love taking photos in that event

5:35 into [music] a singular album of each other through

5:38 an experience that mocks the whole disposable camera experience.

5:41 So, it didn't need to be perfect,

5:42 but it was perfect enough to validate what we wanted to check.

5:46 Another question is, AI.

5:47 I mean, you just built this like 3 months ago.

5:49 Did you just build it with AI tools or what tools did you use?

5:53 Uh it might be a hot take,

5:54 but after we validated with the web app, we threw out the first version.

5:58 And that's because I honestly believe that consumer app is basically a craft.

6:03 And I use a lot of AI for dev,

6:05 for finance, for everything, but for design, we never use AI.

6:09 And that's because we really believe that design requires taste.

6:13 And we think that the more opinionated,

6:15 the better design that could possibly come out.

6:17 But aside from that, I I basically live on Cloud Code.

6:20 Yeah, I mean, I 100% agree with that.

6:23 Design is one of those things that AI is not that good at yet.

6:26 And when you have a B2C app like this, a consumer-facing [music] app,

6:29 you want it to feel This isn't just for utility, this is for fun, creativeness.

6:34 So, I agree on that.

6:35 Let's talk about the tech stack.

6:36 What did you actually use to build this?

6:38 All of our designs live inside Figma.

6:39 And for the [music] dev part, feel like I I'm stuck with Cloud Code.

6:44 And I started off with just a single terminal instance of Cloud Code Max,

6:48 but I was recommended this tool called Conductor,

6:51 where you can run several instances of Cloud Code

6:53 to work on different [music] work trees at the same time.

6:56 And we use Superbase for our database and back end.

6:59 The web app used to live on Vercel,

7:00 but we still have it running web aspects of the product.

7:03 Okay, cool.

7:03 We talked a lot about building,

7:05 but I think maybe the more important thing here is validating.

7:08 So, tell me about how you validated once.

7:11 I did two things to validate our product and to get the first customers.

7:14 Most obviously thing that you can do is just go through your personal network.

7:17 And what I do is I open up three different tabs.

7:20 I have my X open, I have my LinkedIn open,

7:23 and I have my Instagram or Facebook open up.

7:26 I have my friends list.

7:27 I just go through every single one of them and see who might be a good fit.

7:31 So, literally, I circled everyone who had a potential event coming up,

7:35 and it was four friends who said,

7:36 "Okay, I would love to try it." It was a Halloween party,

7:38 birthday party, one wedding, and one networking event.

7:41 So, this is the second part.

7:43 Now, you have to go outside of your inner circle and really

7:45 try to reach out to everyone who could be your potential customer.

7:49 So, what I did was since once could be used at parties, at events, at weddings,

7:52 I searched on Instagram #wedding, #birthdayparty,

7:57 and cross-platform we had around 250 to 300 people listed out.

8:00 I wrote down a very simple cold message

8:03 type of two to three sentences max that could

8:05 grab their attention and try to pitch your idea so that they can try it out.

8:08 Amongst the 250 people we got around 15 people who reached back and we got

8:12 around 12 events fixed for that single month

8:15 and that's when me and my co-founder decided,

8:18 "Okay, this does have market potential.

8:20 Let's try to go all in and try

8:21 to build out something that's really cool." This is awesome.

8:24 I've never heard of validation in this sort of framing before.

8:28 So, let's talk about this a little bit more.

8:30 You got your app from zero to 20K in basically 83 days.

8:34 If you had to start over today, what would be your playbook?

8:36 Step one would be to define your commitment metric.

8:39 And commitment here means two different [music] things.

8:41 Commitment for yourself and commitment for your potential users as well.

8:45 For yourself, set a specific date and specific number of customers or clients

8:50 or other metrics that you would like to see within that date range.

8:54 And at least you know that this is a finite number of days that you

8:57 are dedicating and investing to validate

8:59 your business in a certain amount of time.

9:01 And the commitment metric of the client

9:03 to signal validation doesn't always need to be payment.

9:07 So, for us it was event hosts using our product within those events.

9:11 So, based on your vertical, based on your product,

9:13 there must be some type of metric that truly represents usage.

9:17 And yeah, once you have that commitment metric out,

9:19 I guess step two would be to exhaust your personal network.

9:22 Just open up all of your social media profiles and try to see

9:26 who you can reach out to, whoever relevant to your ideal customer profile.

9:31 And one of the most important things when talking

9:33 to your friends and family is a very famous concept,

9:36 but it's called the mom [music] test,

9:38 which is if you try to validate a product with your mother,

9:41 she would probably be very excited about whatever you build.

9:43 And that is honestly not the best way to validate your product.

9:47 So, just be honest with yourself so that you are sure that you're

9:49 validating the product as opposed to trying

9:51 to find encouragement for your product.

9:53 So, that's step two.

9:54 Well, step three is the real part, which is to build a quick mock-up.

9:57 Don't spend more than two to three days with this.

9:59 Just [music] go on Figma or just use many of these AI tools that's out there.

10:03 No matter how crappy it is, just try to find that really simple [music]

10:07 product that you can present to your users.

10:08 And once you have that, step four is to go

10:10 wherever your users are living in and are active in.

10:14 Just start from zero.

10:15 Go to Reddit.

10:15 Learn the ins and outs of Reddit if Reddit [music] is the place to be,

10:18 or if that's TikTok, or if that's YouTube.

10:20 Because this channel will not only be used for validation,

10:23 but if the validation works,

10:25 it'll be your main marketing channel in the future also.

10:27 So, do so much cold mailing, cold messaging.

10:30 Honestly, what I tell other friends and founders is that if

10:33 you haven't been banned in these platforms at least two times,

10:36 you haven't tried enough.

10:37 And step five is to set that number that gives

10:40 you enough signal or confidence that this product has potential.

10:44 [music] For us internally, the goal was simple.

10:46 Before writing a single line of code, I needed 10 events with an actual date,

10:51 with an actual commitment that they would like to try using our product.

10:54 Having a commitment to actually use at an event where you have your friends,

10:57 your family, your loved ones there, we thought that was already a big enough

11:00 commitment that it was almost proxy to a payment.

11:03 And so, this would be the exact playbook that I

11:04 would be using if I had to start all over today.

11:07 Well, I love this validation playbook.

11:09 I think a lot of people watching this go rewind, start it over, watch it again.

11:13 This sort of commitment metric, this restraint thing sounds scary.

11:16 It sounds hard, but it will save you so much time not building the wrong thing.

11:20 So, I love that.

11:21 Let's switch topics a little bit.

11:22 And I want to see your app.

11:23 Can you give me a demo of your app that made over $20,000 last month?

11:28 Our app is really simple.

11:29 And what you can do is create your own film.

11:32 You name your own film, let's say Brian's party.

11:36 And you can choose the date it ends, choose when your photos reveal,

11:40 like a disposable camera, your filters,

11:44 some of the invitation card when you invite your guests.

11:47 And you can also choose how many participants

11:50 you want to invite and the shots per person.

11:52 You wait out until your film is created.

11:54 Once it is, you can start taking photos and yeah, like a disposable camera,

12:00 this will all be saved up and based on your reveal settings,

12:03 this might reveal later or might reveal now and you can check everyone's

12:07 photos in this album where everyone's photos all gather up in one area.

12:12 Cool.

12:13 Okay, well, that's an awesome app.

12:14 I love apps like this, super cool.

12:17 Last question that we ask all founders who come on Starter Story,

12:20 what would be your advice to young Brian or for anyone watching

12:23 this who wants to come up with a cool app idea like you,

12:25 make money, do indie hacking, what would be your advice?

12:28 I think the most important would be to [music]

12:30 stop overthinking and just launch.

12:32 Because I used to be a person who overthinks a lot.

12:35 How do I do marketing?

12:36 How do I do sales?

12:37 And all blah blah blah.

12:38 But I realized that those are really not the most

12:40 important things if you're trying to go zero to one.

12:44 [music] Rather, just spend that time talking to more users and just building out

12:47 the very first version in like a week [music] or two maximum and just launch.

12:52 Because all of your assumptions and all of your guesswork may

12:56 go to nothing once you launch and once users start using it.

13:00 You might be solving a whole new

13:01 different problem than what you were initially expecting.

13:03 So, really stop overthinking and launch [music] as fast as possible.

13:07 Thanks for coming on, Brian, and sharing.

13:09 Super cool app.

13:10 I think it's going to grow a lot.

13:11 Thanks for coming on and sharing everything.

13:13 All right, man.

13:13 Thanks a lot.

13:14 All right, Gus from Starter Story.

13:16 What do you think of this business, this app, Once Film?

13:19 First thought is really cool product.

13:21 A lot of mobile app founders we talked to, I

13:23 feel like we've seen it before to some degree.

13:25 I haven't exactly seen an app quite like this.

13:28 I know it probably does exist.

13:30 But that's my first thought is like just a cool product and like a cool dude.

13:33 A lot of people have weddings and want this sort of thing

13:35 in this like social media organic world that we live in.

13:40 I had a wedding, you had a wedding.

13:42 I'm sure you get all these like professional photographs,

13:45 but they're like super lame and you don't even post those to social media.

13:48 You just post like the selfies you took or or whatever.

13:51 So I actually think this is like from a growth perspective,

13:55 this app is going to be huge.

13:57 Maybe we can have him back on the channel

13:58 when I think it's going to grow fast and hits,

14:00 you know, a million dollars a year or wherever it

14:03 gets and we can talk more about the growth of that.

14:05 So let us know in the comments if you want

14:08 to see us talk more about how he grew that.

14:10 I think his validation strategy was really smart.

14:13 What do you think about that?

14:14 Yeah, that was it was really like compelling cuz, you know,

14:17 I've tried to start like my apps and stuff like that and I

14:20 totally fall into the trap of [music] like building it first.

14:23 And with Claude Co and all these AI tools,

14:26 it makes it so easy to do it and then avoid the hard part.

14:31 [laughter] You know, when he was when he was talking about like

14:33 go through your contacts and reach out to people, man,

14:36 I could feel myself sort of like cringing up

14:38 a little bit like I can't imagine like messaging

14:40 a random person from 10 years ago when I

14:42 went to college and being like, "Hey, I built this.

14:43 Like, what do you think?" But I

14:45 think that's definitely like a beginner's mindset.

14:49 You're spot on with that.

14:51 Before when it was hard to build stuff,

14:52 you had to ask people and then decide you would build it.

14:55 That would be like the natural way to do things cuz you just couldn't build it.

14:59 Now I think that AI tools are such a crutch in that sense is that like,

15:03 "Oh, I have a cool idea." Instead of talking to people,

15:05 I'm just going to build it.

15:06 Then you build it, it works and it's awesome.

15:09 And then you don't know what to do next.

15:10 You're scared, it doesn't exactly look as good as you wanted it to.

15:13 So then it, you know,

15:14 maybe demotivates you from doing this very, very important thing,

15:18 which is sharing it with random people that you haven't talked to in 10 years.

15:22 This is the scary stuff.

15:23 So, hopefully a lot of people watching this realize that, "Oh,

15:26 in a world where anyone can build anything in 1 hour, this is the secret sauce.

15:31 Going out and setting your commitment metric of I need 10 people

15:36 to say they're going to use this thing before I finish it." So,

15:40 if you're thinking about doing the same,

15:42 you may even build some stuff before or you're thinking

15:44 about jumping into Cloud Code and starting to build an app,

15:47 stop right there and instead go click the link in the description

15:51 to learn about how to actually grow and validate a mobile app.

15:54 We put together the top growth strategies for growing a mobile app,

15:59 an iOS app, a B2C app.

16:01 You can click that right down there in the description and get it 100% for free.

16:04 All right, I hope you guys enjoyed this episode of Starter Story.

16:07 We'll see you in the next one.

16:08 Peace.