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

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

Meet Brian. Him and his girlfriend built a really simple mobile app, and in less than 3 months, they grew it to over $20,000 a month.

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

You might think he validated the idea like everyone else, but no. He did

something I've never seen before, and it's called the commitment metric.

We made sure that people committed to this product before writing a single line of code. So, I brought Brian onto the channel to break it all down for me.

And in this episode, we'll dive into the amazingly simple app that makes over $20,000 a month, why you should resist the temptation to build anything until

you hit this one number, and the new framework to validate business ideas in an AI world. This one is a great story.

So, let's dive in. I'm Pat Walls, and this is Starter Story.

All right, welcome Brian to the channel.

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

Hey Pat, nice to meet you. My name is Brian Shin, and uh we built a disposable camera app called Once. We launched back in December 2025, and fortunately, we were able to hit 20K in monthly revenue

within 83 days of launch. So today, I really want to share exactly how we pre-validated once before writing a single line of code and also some of the growth playbooks that we had to grow ones from zero all the way to $20,000 in

monthly revenue.

Okay, cool. I mean, awesome to have you here. Would you be able to just explain

here. Would you be able to just explain what your app does, who uses it, and pull up some of your revenue dashboards to show that this is legit to the audience?

Yeah, for sure. So, ones is basically a disposable camera for events, especially for weddings, birthday parties, and these days even for some corporate events. So, anything where a group of

events. So, anything where a group of people can come together, have fun, and capture all the candid moments once can play a role there. And our pricing is based on the number of guests that you

want to invite into your event. So if

it's like a small birthday party with just 10 people, it's going to be just $2. But if it's like a bigger wedding,

$2. But if it's like a bigger wedding, for instance, if it's like 150 people, it'll be $50. So that's the more usage, the more guests, the more um higher tier that you would need to purchase in order

to use once. So it's been around 3 months since launching. And our weekly active users is around 10,000 to 12,000 users at the moment. And in terms of revenue this month, we're totaling around $22,000.

And this is our internal dashboard calendar where you can see all of our active users who have scheduled an event through once. And as you can see in

through once. And as you can see in February, there are around more than 300 events. And for March, we got around 700

events. And for March, we got around 700 events coming up real soon. Here's what

I love about Brian's story. It's a great example of someone who focused on growth and then hit $20,000 a month in less than 90 days. And this got me thinking.

We talk to dozens of mobile app founders every week right here on this channel.

And I always ask them the same question.

How did you actually grow your app?

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right now. It's called the mobile app growth cheat sheet. And inside you will find the seven different marketing tactics that are working for real founders right now making money with

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for free. I promise it won't disappoint.

All right, let's get back to the episode. Okay, cool. I mean, this looks

episode. Okay, cool. I mean, this looks like a really cool app. I can see why it's popular and why it's growing. I

want to understand a little bit about your background. How do you get to this

your background. How do you get to this point where you're building this cool consumer app that over 300 people are about to use this month at events?

What's your background?

So, before founding ones, I co-founded a venturebacked B2B startup. It's

completely different from one's. It was

more of a heavy salesdriven 50 person company. So building this a ventureback

company. So building this a ventureback startup really showed me what a real business is and everything related to building a fast growth company. And

while I was at the company, I found the whole bootstrap scene which I didn't know existed before. I met all these really cool indie hackers and bootstrap founders who are validating in a very

small way. So it's rather a safer,

small way. So it's rather a safer, smaller bet as opposed to betting your whole life on something that's bigger.

And I don't think there's right or wrong here, but I really wanted to try this new path of building a bootstrap company. And that's why this time I

company. And that's why this time I really wanted full control over the product that we build. Hence, me and my co-founder, my girlfriend, we decided to go fully bootstrapped this time.

Okay, cool. Let's switch topics a little bit and talk about the idea. So, how do you actually find the idea for this app that eventually makes over $20,000 a month?

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

last year, we traveled to almost seven, eight different countries, and every single city we go to, we bring around a disposable camera. If you tried using a

disposable camera. If you tried using a disposable camera, it's such a simple product, but it's so magical in a way that it has so many limitations. You

can't see the photo right away. You have

limited amount of shots. But I think those limitations, it actually makes the whole experience much real. So really

the whole idea behind once was why don't we try to build a digital experience that almost replicates that traditional disposal camera was the whole idea behind it.

That's awesome. Let's talk about how you built this app. How long did it take to build this app and what was that journey like?

So the first version took around a week or two. It was a web app that kind of

or two. It was a web app that kind of just had the core features of what a mobile app intended to have. We had a Halloween party hosted by my friend coming up. So we built out this web

coming up. So we built out this web version. We printed out some invitation

version. We printed out some invitation codes so that everyone in the party can join in, take photos, and honestly it broke many times during the event. But

we were able to validate the core idea that the people loved taking photos in that event into a singular album of each other through an experience that mocks the whole disposable camera experience.

So it didn't need to be perfect, but it was perfect enough to validate what we wanted to check.

My other question is AI. I mean, you just built this like 3 months ago. Did

you just build it with AI tools or what tools did you use?

Uh, it might be a hot take, but after we validated with the web app, we threw out the first version. And that's because I honestly believe that consumer app is

basically a craft. And I use a lot of AI for dev, for finance, for everything.

But for design, we never use AI. And

that's because we really believe that design requires taste. And we think that the more opinionated, the better design that could possibly come out. But aside

from that, I I basically live on cloud code. Yeah. I mean, I 100% agree with

code. Yeah. I mean, I 100% agree with that. Design is one of those things that

that. Design is one of those things that AI is not that good at yet. And when you have a BTOC app like this, a consumerf facing app, you want it to feel this isn't just for utility. This is for fun,

creativeness. So I agree on that. Let's

creativeness. So I agree on that. Let's

talk about the tech stack. What did you actually use to build this?

All of our designs live inside Figma.

And for the dev part, feel like I I'm stuck with cloud code. And I started off with just a single terminal instance of cloud code max. But I was recommended this tool called conductor where you can

run several instances of cloud code to work on different work trees at the same time and we use superbase for our database and backend. The web app used to live on versel but we still have it running web aspects of the product.

Okay, cool. We talk a lot about building but I think maybe the more important thing here is validating. So tell me about how you validated once.

I did two things to validate our product and to get our first customers. The most

obvious thing that you can do is just go through your personal network. And what

I do is I open up three different tabs.

I have my X open, I have my LinkedIn open, and I have my Instagram or Facebook open up. I have my friends list. I just go through every single one

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

So literally, I circled everyone who had a potential event coming up. And it was four friends who said, "Okay, I would love to try it." It was a Halloween party, birthday party, one wedding, and one networking event. So this is the

second part. Now you have to go outside

second part. Now you have to go outside of your inner circle and really try to reach out to everyone who could be your potential customers. So what I did was

potential customers. So what I did was since once could be used at parties, at events, at weddings, I searched on Instagram # wedding # birthday party and crossplatform we had around 250 to 300

people listed out. I wrote down a very simple cold message type of two to three sentences max that could grab their attention and try to pitch our idea so that they can try it out. Amongst the

250 people, we got around 15 people who reached back and we got around 12 events fixed for that single month. And that's

when me and my co-founder decided, okay, this does have market potential. Let's

try to go all in and try to build out something that's really cool.

This is awesome. I've never heard of validation in this sort of framing before. So, let's talk about this a

before. So, let's talk about this a little bit more. You got your app from zero to 20K in basically 83 days. If you

had to start over today, what would be your playbook? Step one would be to

your playbook? Step one would be to define your commitment metric. And

commitment here means two different things. Commitment for yourself and

things. Commitment for yourself and commitment for your potential users as well. For yourself, set a specific date

well. For yourself, set a specific date and specific number of customers or clients or other metrics that you would like to see within that date range. And

at least you know that this is a finite number of days that you are dedicating and investing to validate your business in a certain amount of time. and the

commitment metric of the client to signal validation doesn't always need to be payment. So for us it was event host

be payment. So for us it was event host using our product within those events.

So based on your vertical based on your product there must be some type of metric that truly represents usage. And

yeah once you have that commitment metric out I guess step two would be to exhaust your personal network. Just open

up all of your social media profiles and try to see who you can reach out to whoever relevant to your ideal customer profile. And one of the most important

profile. And one of the most important things when talking to your friends and family is a very famous um concept, but it's called the mom test, which is if you try to validate a product with your mother, she would probably be very

excited about whatever you build. And

that is honestly not the best way to validate your product. So just be honest with yourself so that you are sure that you're validating the product as opposed to trying to find encouragement for your product. So that's step two. Well, step

product. So that's step two. Well, step

three is the real part which is to build a quick mockup. Don't spend more than two to three days with this. Just go on Figma or just use any of these AI tools that's out there. No matter how scrappy it is, just try to find that really

simple product that you can present to your users. And once you have that, step

your users. And once you have that, step four is to go wherever your users are living in and are active in. Just start

from zero. Go to Reddit. learn the ins and outs of Reddit if Reddit is the place to be or if that's Tik Tok or if that's YouTube because this channel will not only be used for validation, but if the validation works, it'll be your main

marketing channel in the future also.

So, do so much cold mailing, cold messaging. Honestly, what I tell other

messaging. Honestly, what I tell other friends and founders is that if you haven't been banned in these platforms at least two times, you haven't tried enough. And step five is to set that

enough. And step five is to set that number that gives you enough signal or confidence that this product has potential. For us internally, the goal

potential. For us internally, the goal was simple. Before writing a single line

was simple. Before writing a single line of code, I needed 10 events with an actual date with an actual commitment that they would like to try using out the product. Having a commitment to

the product. Having a commitment to actually use at an event where you have your friends, your family, your loved ones there. We thought that was already

ones there. We thought that was already a big enough commitment that it was almost proxy to a payment. So, this

would be the exact playbook that I would be using if I had to start all over today.

Well, I love this validation playbook. I

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

This sort of commitment metric, this restraint thing sounds scary. It sounds

hard, but it will save you so much time not building the wrong thing. So, I love that. Let's switch topics a little bit.

that. Let's switch topics a little bit.

I want to see your app. Can you give me a demo of your app that made over $20,000 last month?

Our app is really simple and what you can do is um create your own film. You

um name your own film. Let's say Brian's um party. And you can choose the date it

um party. And you can choose the date it ends. Choose when your photos reveal

ends. Choose when your photos reveal like a disposable camera, your um filters, some of the um invitation card when you invite your guests, and you can

also choose how many participants you want to invite and the shots per person.

You wait out until your film is created.

Once it is, you can start taking photos and yeah, like a disposable camera, um, this will all be saved up and based on your reveal settings, this might reveal later or it might reveal now. And you

can check everyone's photos in this album where everyone's photos all gather up in one area.

Cool. Okay. Well, that's an awesome app.

I love apps like this. Super cool. Last

question that we ask all founders to come on Starter Story. What would be your advice to young Brian or for anyone watching this who wants to come up with a cool app idea like you make money do indie hacking? What would be your

indie hacking? What would be your advice?

I think the most important would be to stop overthinking and just launch because I used to be a person who overthinks a lot. How do I do marketing?

How do I do sales? LA. But I realized that those are really not the most important things if you're trying to go zero to one. rather just spend that time talking to more users and just building

out the very first version in like a week or two maximum and just launch because all of your assumptions and all of your guesswork may go to nothing once you launch and once users start using

it. You might be solving a whole new

it. You might be solving a whole new different problem than what you were initially expecting. So really stop

initially expecting. So really stop overthinking and launch as fast as possible.

Thanks for coming on Brian and sharing.

Super cool app. I think it's going to grow a lot. Thanks for coming on and sharing everything.

All right, man. Thanks a lot.

All right, Gus from Starter Story. What

do you think of this business, this app?

Once film, first thought is really cool product. A lot of mobile app founders

product. A lot of mobile app founders we've talked to, I feel like we've seen it before to some degree. I haven't

exactly seen an app quite like this. I

know that probably does exist, but that's my first thought is like just a cool product and like a cool dude. A lot

of people have weddings and want this sort of thing in this like social media organic world that we live in. I had a wedding. You had a wedding. I'm sure you

wedding. You had a wedding. I'm sure you get all these like professional photographs, but they're like super lame and you don't even post those to social media. You just post like the selfies

media. You just post like the selfies you took or or whatever. So, I actually think this is like from a growth perspective, this app is going to be huge. Maybe we can have him back on the

huge. Maybe we can have him back on the channel when I think it's going to grow fast and hits, you know, million dollars a year or wherever it gets and we can talk more about the growth of that. So,

let us know in the comments if you want to see us talk more about how he grew the app. I think his validation strategy

the app. I think his validation strategy was really smart. What did you think about that?

Yeah, that it was really like compelling cuz you know, I've tried to start like my apps and stuff like that and I totally fall into the trap of like building it first and with cloud code

and all these AI tools, it makes it so easy to do it and then avoid the hard part. you know, when he when he was

part. you know, when he when he was talking about like go through your contacts and reach out to people, man, I could feel myself sort of like cringing up a little bit. Like I can imagine like messaging a random person from 10 years

ago when I went to college and being like, "Hey, I built this. Like, what do you think?" But I think that's

you think?" But I think that's definitely like a beginner's mindset.

You're spot on with that. Before, when

it was hard to build stuff, you had to ask people and then decide you would build it. That would be like the natural

build it. That would be like the natural way to do things cuz you just couldn't build it. Now, I think that AI tools are

build it. Now, I think that AI tools are such a crutch in that sense is that like, oh, I have a cool idea instead of talking to people. I'm just going to build it. Then you build it, it works,

build it. Then you build it, it works, and it's awesome. And then you don't know what to do next. You're scared. It

doesn't exactly look as good as you wanted it to. So then it, you know, maybe demotivates you from doing this very, very important thing, which is sharing it with random people that you haven't talked to in 10 years. This is

the scary stuff. So, I hope a lot of people watching this realize that, oh, in a world where anyone can build anything in 1 hour, this is the secret sauce, going out and setting your

commitment metric of I need 10 people to say they're going to use this thing before I finish it. So, if you're thinking about doing the same, you might even built some stuff before or you're

thinking about jumping into Cloud Code and starting to build an app. Stop right

there and instead go click the link in the description to learn about how to actually grow and validate a mobile app.

We put together the top growth strategies for growing a mobile app, an iOS app, a B TOC app. You can click that right down there in the description and get it 100% for free. All right, I hope

you guys enjoyed this episode of Starter Story. We'll see you in the next one.

Story. We'll see you in the next one.

Peace.