Before you build an app, check if it already exists
Before you write a line of code, spend 30 minutes finding out whether the thing you're about to build already exists. Most app ideas do, and not only as competitors you'd size up. Some already exist as finished, working software you can license and start from. Checking first is the cheapest step in the whole project, and skipping it is how people spend 3 months rebuilding something they could have bought in an afternoon.
The planning-stage question isn't only "is my idea taken." It's the more useful one. Does a working version already exist that I could start from, instead of starting from an empty repo?
Why check before you build?
Because almost every app is a variation on one that already exists, and some of those exist as code you can buy. Most people check the first thing, whether there are competitors, and never check the second, whether they can start from an existing build. That second check is the one that saves months. If a close-enough version already runs, licensing it and changing what makes yours different is faster than writing the whole thing to arrive at the same place.
This isn't giving up on your idea. It's refusing to rebuild the 80% that every app in the category shares, so you can spend your time on the 20% that's actually yours.
How do you actually check?
Three searches, in order, before you scaffold anything.
- Search the open market. Google, the app stores, Product Hunt. This tells you what your users already have. There are step-by-step ways to check whether your idea is taken, but they usually stop at competitors and skip the next two steps.
- Search open source. GitHub and the package registries. Sometimes the thing exists, free, and your job is hosting and polish rather than building.
- Search software marketplaces. This is the step people skip. A finished build you can license and deploy is often listed for a fraction of what it costs to write. You can browse what exists by category to see whether your idea is already a product you could start from.
Write down what you find in each. The goal isn't a competitor spreadsheet. It's an honest answer to one question: is there something here I could start from?
It already exists. Should you still build it?
Sometimes yes. Here's how to tell.
| Build it from scratch when | Start from an existing build when |
|---|---|
| Your version is genuinely different at the core | The difference is branding, a few features, or a niche |
| Building it is the point, because you're learning | You want to be live and testing this month |
| Nothing you found actually fits | A close-enough version exists you can rebrand and extend |
| You need control of every decision | The plumbing is generic and you'd only rebuild it |
Most ideas land on the right-hand side more often than you'd expect. The parts that feel like the product, the auth, the billing, the dashboard, the standard flows, are usually the parts everyone else already built too.
What does "start from an existing build" mean?
You license the code and make it yours. On a marketplace like this you pay once for a non-exclusive, worldwide, perpetual license to use, modify, and deploy the software. You own your copy, change whatever you want, and deploy it under your own name. You skip the weeks of boilerplate and put that time into the part that's different. There's no revenue attached and no company changing hands. It's the head start you're buying, nothing more.
When building from scratch is still the right call
- The core is genuinely new. If the thing nobody has built is the whole point, build that part and buy the plumbing around it.
- You're building to learn. Then the building is the goal, and a shortcut defeats it.
- Nothing fits. You checked, and what exists is wrong for your users. Now you're building from scratch on purpose, which is a stronger place to start than never having looked.
Common questions
Isn't checking first just talking myself out of building? No. It's making sure the months you spend go into the part that's yours, not the part a hundred other apps already have.
What if my idea exists but the versions are bad? That's a reason to build, or to buy a foundation and make it good. Either way you learned it in an afternoon instead of in month three.
Where do I look for a build I can start from? Software marketplaces list finished, deployable software by category. Browse by category or the full marketplace to see what's there.
If it turns out the move is to start from something that already runs, launching without building from scratch covers how that goes, and buying software instead of building it makes the wider case.
