A Simple Height Prediction App Earns $100,000 Monthly

When I heard about this app idea, I started cracking up because I thought there's no way this thing actually makes any money until I found out just how much it was making. I am 20 years old. I built an app called Go Tall that now makes on average about 100K a month. This is Michael. He's a 20-year-old college student who came across his idea inside the comments of a Tik Tok video. Instead of continuing to scroll, he decided to build the thing and it worked. After two days of launching it, I already had the first sale.

I asked Michael to come on to the channel to break this all down. In this episode, we'll dive into his unbelievable app idea that makes $100,000 every month, how he knew before that this was an idea that could blow up, and his advice for finding other mobile app ideas that could make over $100,000 a month. All right, this is one you cannot miss. I'm Pat Walls and this is Starter Story. All right, Michael, welcome to the channel. I am super pumped to have you and talk about this super cool app that you built. So, tell me, who are you? What did you build? And what's your story? So, my name is Michael. I am 20 years old in college and last summer I built

an app called Go Tall that now makes on average about 100K a month. So, yeah, I'm excited to share about the idea behind it, how I came up with it, and just walk you through uh my growth strategies. All right, so you're doing 100K per month with a height predictor app. I don't really even know what that means, but we're going to get all into it. I'm super excited to talk about it, but before we do, uh, let's prove this. I want to make sure that this is legit. Would you be able to pull up some of your revenue numbers, your website, show me what the app does, and show me how much revenue this thing is actually making? The premise of the app is more

so that it is a height prediction app and then we try to put you know things on there to help like teenagers better optimize their habits and hopefully through that they can naturally actually reach their max like potential height. It's a pretty uh standard subscription. We have a $35 yearly uh $5 weekly plan. Um and then if users don't want to pay that we have sort of a premium onto our app where they can access still access you know fe different features. This is my apps for connect by sales. This is my daily sales from January till now. This is my super wall of new users broken down by monthly. Yeah. So I have about 700,000 downloads on the app store and then a couple hundred thousand on Android as well. So, it adds up to be

about a million downloads overall. Thanks for sharing that. $100,000 a month with an app. You mentioned that you are still in college and you're 20 years old. That's absolutely crazy. So, I got to hear how do you get here? Like, how do you get to the point where you haven't even graduated college and you have this app that is making over $100,000 a month? Yeah. You know, I was a student at NYU. I was a finance student. I was recruiting for the jobs and I basically got rejected from like all of my dream jobs at the time. I was really seeing so it was last summer I was seeing a lot of

startups take off on good marketing and I just felt like I could do it myself as well. When I was a teenager, I was developing my own apps even before like AI, but I was just never really good at marketing. And I thought to myself, I had to learn marketing. And so I was just doing any app idea that I could find. This was one of the first ones I thought had potential. And I was like, even if this app failed, at least I would come out with the skills of like how to do marketing. I love Michael's approach to finding ideas and thinking about customer pain points. His idea is proof that literally any app idea can make money if you think about it the right way. But I think one of the secrets behind this app's success

is simply that it's built in a pretty smart category, which is health and self-improvement apps. I think this is a great place to be building, and it's exactly why I put together the health, wealth, and self-improvement app ideas database. Inside this database, you'll find over 50 successful app ideas in the space. And we'll break it all down, including monthly revenue, startup cost, tech stack, and the real data behind these actually successful businesses. If you're looking for your next idea or you're looking for a good problem to solve, just head to the link in the description and you can grab the database 100% for free. All right, let's get back to the episode. One of my favorite uh stories when I hear founders

who you know suffered some sort of rejection like you didn't get the your dream job you're looking for so you said screw it I'm going to go build apps. Similar story for me is I was working in a job that I didn't like. I just wanted to build something cool. I wanted something different. So that's that's awesome. Let's let's move a little bit to the idea cuz this idea is crazy. It's almost preposterous this height predictor app but it's obviously crushing it. So let's talk about how did you find this idea and then second how did you know it was a good idea and worth like throwing everything into?

I first saw this idea when I was looking on website literally websites like acquire.com cuz I was like I don't know any good ideas. I want to find a validated idea and I saw an app that's pretty similar to this for sale for around $20,000. And then I thought to myself like wait actually this is definitely a real problem because I was when I was 13 years old I was looking up like height calculator on Google or something. So that's when I began like building it and then I remember like after 2 days of launching it I already had the first sale and that was also a huge amount of validation for me because I didn't even get that many views and I was like wow people really want this.

And then the second thing is that on Tik Tok, if you just look at any sort of height video in general, I would see people saying like, "Oh, I am six foot. I'm 15. My mom's this height, my dad's this height." People just want to give that information and I assume like they wanted to get predicted. And so, one of my first viral formats was just replying to those comments and predicting their height. Dude, that's super cool. Well, there's two things you mentioned that I think are like really cool is that you went on acquire.com and you found an idea that was already proven. You didn't buy it, I'm assuming, and you went and just

built it yourself. You've talked to other founders who have done the same thing. So, I think that's a super cool little tactic that you mentioned there. But more importantly, what you did is you remembered a personal problem that you had and then you further validated that cuz you're a little older now. Then you further validated that by going into actual Tik Tok comments and further validating that people were experiencing these problems. All good business ideas come from problems, solving problems. So, I think that's super cool. On that note, what would be your advice for other people who are watching this right now who want to find an app that's crushing it like yours? What would be

your advice for those people watching right now? I would say there's just like so many more ideas that can be successful that people thought like I feel like a lot of people they see that some ideas already existing and then they're just like, "Oh, I'm out." You know, like I'm not going to build this anymore. Whereas even in today's age, like there's still calorie trackers doing 30K a month when you have Cali. Like that does not make sense to me at all. And I feel like just seeing that sort of phenomenon happening, it just proves that no idea like has already done before. And you can always try to do the same idea someone else did and still make it successful uh with your own tweaks and things like that. The other thing you

want to make something that really hits with people's needs. I had my TikTok and I would have like 10 20 DMs a day of people requesting their height to be predicted. People were like really care about this like height prediction thing. There's some problems that you can really just see and you're like wow this is an actual painful problem. I think the Masle hierarchy of needs is a really good framework for like what do people like want? If you think about your app idea ideally it can fit into like one of these categories. the more like things it hits, the better. So, for example, for me, the height prediction app one, it hits the esteem part because people want to know that they're going

to be tall because they want, you know, respect from other people. Height is that and also love and belonging. Maybe they feel like, you know, getting tall is the only way they can get like a girlfriend. It hits two of the five. When you think about your app and think about the Masos Harkin needs, you can better think about like, oh, is my app actually going to be useful to people? Okay. So, you mentioned something again. We're thinking about apps that have demand and you clearly had demand and you mentioned something really key here is that like you noticed that people really cared. They cared about their

height. They cared enough to send you a DM. Often, a lot of times when we build startups, we build something and then we get no DMs. So, that's just such a key insight there that you noticed because you're getting those DMs, you noticed that people cared, therefore it was an app that could make $100,000 a month. So, I think that's super cool and kind of low-key genius. Let's move on to the growth because obviously anybody can build a height predictor app. You could probably do it in a few hours with my claude code right now. How did you get this app users and ultimately get it to $100,000 a month?

First it was me just making content myself. It took about a month of just experimentation purely with content. I'm making 10 Tik Toks every day. So then eventually I found the format because I only had one format. I had one distribution channel. It's very easy to see the attribution. Like I know exactly 100K views equals how many downloads. And then based off that I'm like, okay, now I know I can hire creators for this amount of price. With the format, I replicated it myself on like two different accounts and they both blew up. I had my girlfriend do it too and like her account blew up and I was like, "Okay, this is like an easy format. I can like teach anybody." So I just went

on DM'd like 50 people a day to be like, "Hey, would you want to make format make this video? It's super easy." And so they were able they were willing to do it for a very cheap price. Basically just myself plus a few UGC creators, we were able to do maybe like 3K a month. After I optimized my payw wall and scaled a little more, it was about 10K a month. In month five, it was about 30K a month as I explored even more formats. And after 30K a month, uh it was simply just putting it on paid ads to scale to over 100. Yeah, that's this is the classic playbook that uh we hear a lot these days now is you kind of crack UGC, you figure out what kind of organic content works and then you just put ads behind

that content that you know already works and then it works even better with ads. So, um that's super cool. Thanks for sharing that. Let's talk about the tech stack. What's the tech stack behind this app that makes over $100,000 a month? Yeah, I'd say tech stack is very cheap. Used Expo to make it so that it's both iOS and Android super wall for pay walls and then we use Adapti as well in order to get advanced payouts since you know Apple's payout cycles are brutally long. Uh and then I use a MMP. I use a singular MMP for 3 cents per install. Cool. Simple tech stack. Okay. Now I'm I'm excited to see the app. I like talking about the idea, how you built it, the growth, all that stuff. But now

I want to see what this app is. Can you show me the height predictor app that makes $100,000 per month and give me just a demo of how it works so that we can see? What I'm most proud of is the onboarding. Basically, as I'm predicting the height, the users kept on giving like more of their own information to the comment because they want a more accurate height prediction. And so that just resulted in the onboarding being like super long. The more information that you can get, the more predictive of the height you could be. Exactly. And then the app actually does in the beginning it didn't but it actually pulls a lot of like research papers to actually give the high

prediction. So the base is like the CDC data of like you know whatever your doctors gives you at the doctor's appointment. But then all these other questions have like links to research studies that we use to adjust your like final height. So this is like a puberty quiz. This will see like where you are in puberty and that would have a very big effect of like how much you actually are. And this payw wall has about like a 91% payw wall show rate despite being pretty long. Yeah, I'm kind of just skipping over everything because I've seen this like a hundred times. And do you have to um pay and subscribe for the app to see the ultimate prediction?

Yes, correct. So that part is paid, but you can do sort of you know stretches, you know, you can scan meals and you can log your sleep. And the whole thing is that your height prediction is going to like change as the weeks go by. The more you actually log it on the app, since like we can see how much you've been growing, it will actually give you like the most accurate height prediction. You get them in the door with this height prediction, which everyone is excited to see what it is, but then you keep them on subscription over. What kind of habits can I do to help potentially? Obviously, there's no guarantees you're going to increase your

height. It's a lot of genetics and things like that, but maybe there are some habits that can help you, you know, get a little bit more marginal gain from it. Yeah. I'm super happy that like people really finding value. All right, cool. Well, thank you for sharing the app. Super cool app. Simple app. I like simple. I love simple. Hopefully, you're watching this and you realize it doesn't need to be complicated to make money and have a successful app. Last question that we ask all founders that come onto the channel. If you could go back in time to, you know, younger Michael when you

were interviewing for jobs, you got rejected from your dream jobs, you wanted to build something, what would be your advice to younger Michael before you built this app or for anybody watching this who wants to do the same? Something that I think would actually be helpful. I am from an environment where people are going to do prestigious corporate jobs or if they're going on the startup space, they're going raise billions of dollars from VCs onto some solving some really complex problem. Last summer, I basically just got rid of my ego. Doing this hyperrediction app gives me zero like social status or anything. It's it's a huge like embarrassment. I remember I would go to people, I'm like, "Yeah, I'm building a

hype prediction app." And people are just like, "Yeah, like good luck." Right? I feel like there is gems when you're willing to completely let your ego go. Go make the stupid Tik Toks. Go do the idea that you think has potential even though it's so unglamorous. So, I feel like at least with my story, I think that's what's the example of letting yourself away from that social pressure. No, that's great advice and it's really cool that you figured that out at such a young age. There's a saying, I can't remember what it is, but in order to be successful, you need to uh climb up cringe mountain and you need to make it

to the top of cringe mountain and once you get to the top of cringe mountain, then you'll be successful. And I think that's actually really good advice and clearly it worked for you. So, thanks Michael for coming on, dude. Super cool app. though. Thanks for coming on, man. Thank you so much, Pat, and thanks for asking all the insightful questions. I had a great time. All right, Gus, producer of Starter Story. What did you think about this one? Yeah, my instant reaction, which is why I wanted to have him on the channel, was like, I always see these there's this guy on Twitter I follow. It's always

just posting random ideas and I'm always like, man, who are the people behind this app? This is one of those ideas I saw and I was like, a hype prediction app? Like, what is that? How does that make money? How did he find the idea? my reaction is just like just so like unbelievable that people for this, but when he described it, I was like it makes a lot of sense. It's not like it's not out of this world. So those are my some initial thoughts. When I first saw when he explained what his app did, it's like okay that's cool. And then I was like that probably maybe does 10k a month like kind of maxed out and he's like, "Oh, it does 100k a month." I was like, "Oh my gosh." Like and then you're right, I started to put

the dots together and think, "Okay, well this is a really common problem that all people have. They want to be taller. You want to be taller." The most interesting thing for me was that he actually kind of started by creating content. And when he was creating this content on TikTok, super easy content to create, people were messaging him, hey, can you predict my height? He saw that and he said, hey, okay, it's cool. They're asking for me to my height and I can make videos about it. That's cool. But I think it can be actually even bigger. Doesn't need to go viral first to know it's going to be something big. People just need to care.

Yeah. It just reminds me like I think he said this at the end but like whatever success is like climbing cringe mountain or something like that is what you said and I feel like that is the number one thing that has held me back and probably a lot of people watching is like the inability feel cringe or put themselves out there share an idea and risk essentially risk like feeling stupid or like you know whatever getting hateful comments etc. But when you if you can get by that like he was saying at the end doesn't mean you're going to like always obviously make 100k per month but you're going to find an idea or read a comment or get a weird DM that leads to XYZ thing.

Yeah. No, it's really easy in hindsight to look back and be like, "Oh, that was successful. Of course it was going to be successful." What he mentioned towards the end of our interview, what most people don't get is the amount of insecurity and uncertainty when you first have an idea. When you first have a height predictor app and people look at you like you're insane to keep going through something like that. That's where every founder on our channel shines. That's what it means to be a founder is to push through when nobody believes in you. It feels like it's only risk. You're not making any money and that's it. So on that note, if you are looking for ideas like this, I think it's amazing to build anything in the

health, wealth, and relationships space. People experience so much pain and problems in this space. If you can solve those problems, I think you can win. So, if you're curious, we put together a list of over 50 ideas in this space. You can download them for free right now. I put them in the description right there. These are real ideas making real money, and you can check them out right now. All right, hope you guys enjoyed this episode. We'll see you in the next one. Peace.