How To Make Passive Income Developing Apps

Opinions expressed by Entrepreneur contributors are their own.

You're reading Entrepreneur United States, an international franchise of Entrepreneur Media.

In the decade since the app economy made its debut, billions have been made off this sweeping online change. Indeed, a lot of millionaires have been made; and more will be made in the coming years, thanks to apps.

scyther5 | Getty Images

Related: 6 Big Challenges Faced By Startups When Developing Mobile Apps

In 2017 alone, the App Store created an estimated $26.5 billion in revenues for app developers. That's a 30 percent increase from 2016, and brings the total amount of money paid to developers up to a staggering $86 billion since 2008.

But, for most app innovators, it's pretty rare to see a new product go from launch to a million dollar money-maker. In fact, the process takes dedication and commitment: You first have to build the app, then scale it.

However, the process is still do-able, and it needn't take long at all.

It all starts with building just one app. And that app can be for any platform you wish, or for all platforms; but it's just one app with one name and one purpose. That's it. From there, you take your app and monetize it.

There are a ton of ways to make money with your app, and more steps than can be discussed in this post, but here are a few of the most straightforward and simple ways to build up a steady cashflow with your app:

Sell a subscription.

You can have a small free version of your app, but leave the best part of it to be unlocked for a consumer subscription costing just a few bucks a month. This is the beauty behind apps like Headspace.

Show some ads.

You have an app, like a game, that people spend a lot of time on; in that case, you can put some ads in to make some money while users enjoy your creation. Electronc Arts is know for doing this, with games like Sim City: Buildit.

Sell a premium version.

You can have a free, or low-cost app. But keep some extra incredible features available for an extra purchase. This is like the "remove ads" feature in any "pro" version of an app; and it's how Sega is monetizing its classics games.

Sell your data.

You can collect anonymous data from your app and its users and sell it to people that need it to run their business. Keep it privacy-compliant, and enjoy a revenue model that doesn't show ads to your users.

For the most part, once an app is built, you're done. Maybe you'll have a few updates here or there, but you can effectively just leave it in the store to get more downloads and take in more revenue. It's just like a website; only you can do much, much more.

And just the way websites were in the '90s, it's an incredibly scalable business model.

Believe it: You can spend a week or two to build an app that eventually goes on to earn you $10,000 per month. That goal will definitely take some work, but there are thousands upon thousands of people doing it today, so it's certainly possible.

Now, here's where the fun starts . . .

You can take what you learned with your first app, and apply it to your next app.

What originally took you a week to build can now be reduced to, say, three days or so -- possibly even a single day, depending on how similar the apps are.

With app number two, you'll be able to scale it to $8,000 per month with the same effort and tactics you used to scale app number one. Think about that for a moment: You spend barely over a week building two apps. How this happened is that you do the exact same thing to scale your second app -- which means it goes a lot faster, and almost doubles your revenue for less than half the work you put into the first app.

What happens when you add in a third app? Or a fourth?

Honestly: The math checks out!

This is the power of scale at your fingertips. This is how app empires are built. Simple apps doing between $1,000 and $50,000 a month can be replicated time and time again until you get bored and leave to find something else to fill your time.

As long as you learn how to build that first app, you can keep scaling your successes endlessly.

It doesn't matter whether you're working full-time. Seriously!

I don't care if you're in a cramped cubicle, and your boss, with his persistent coffee breath, is breathing down your neck as you read this: Creating apps can be done as a side-hustle until you're ready to toss off your "good-bye" as you walk out the door for the last time.

Related: 7 Resources That Can Help You Create a Stunning Mobile App Design

What's more, creating apps is something that can be done by people of any age, even if they don't know the first thing about tech!

You just have to want it. Then, you have to build something. Then you have to get it to earn some money. Rinse and repeat. And keep doing that until you can finally buy your freedom.