So I am in the process of finishing an app (android for now), and I have a doubt about if I should have papers that proof that I made that app.

Its the first time for me to publish an app, and I am concerned about how to prove that I made the app and it belongs to me.

In other words

If I came and asked the instagram app developer, prove that you made this app? What would he show me?

Thanks for your help.


So developers of whatsapp, instagram, skype, ...... have nothing to prove that they made the app? They just publish to the store?

  • He would probably tell you to go away. Unless you want to buy the complete rights to the app, why would he or she waste their time for you?
    – gnasher729
    Jan 26, 2020 at 14:55
  • @gnasher729 the example is just to clarify my question, I mean if authorities asked someone about app ownership what do you show?
    – SomeUser
    Jan 26, 2020 at 14:57
  • If you own the developer account which can publish the app then you essentially own the app.
    – Dan Wilson
    Jan 26, 2020 at 14:58
  • 1
    @RobertHarvey the car has papers? Its the first time for me to publish an app I need to understand so that I dont face problems later.
    – SomeUser
    Jan 26, 2020 at 15:05
  • 3
    For what it's worth, if you develop an app, register with the app store, fulfill their requirements (whatever those are) and then publish the app, it's going to be very difficult for someone else to come along and claim ownership of your program. Jan 26, 2020 at 15:15

4 Answers 4


The usual way is to show that you are the author of the source code.

Unfortunately, if all you have is your source and your goodwill, another party could come with your source and claim it’s theirs and that you only change the copyright. Then, you’d have to litigate and some very expensive forensic expert could eventually prove it’s yours.

So the key for successfully prove that you’re the author is to have a trustable third party that can confirm that you wrote it first. An independent repository (e.g GitHub, GitLab & co) can help you because they control their independent timestamps (on your own files you could manipulate time).

Now in most countries, copyright authorities allow you to deposit your source code. It is not mandatory for owning the copyright, but it greatly helps in case of litigation.

Disclaimer: I’m not a lawyer, I’m just an author who had some personal experiences in that area. So in case of doubt, the best is to consult a lawyer or a qualified legal expert in your jurisdiction

  • How would another party come and with my source if I already registered it with an office?
    – SomeUser
    Jan 26, 2020 at 15:32
  • I mean is it enough to have the developer account and registering a copyright of the source code with the office?
    – SomeUser
    Jan 26, 2020 at 15:36
  • @SomeUser There could always be some litigations. But if as legitimate author you’ve registered the code, I think you have very good cards in hand and the litigator would have to come with strong evidence to challenge your ownership.
    – Christophe
    Jan 26, 2020 at 16:18
  • @SomeUser If you want to know more about how this works and the kind of problems you could be confronted with, I can warmly recommend Bob Zeidman’s book “The software IP detective’s handbook”. He gives a brilliant oversight on all aspects and proof issues. He then goes very deep into technical details,maybe beyond what could interest a non-forensic reader. But fir the first part alone it’s a great investment :-)
    – Christophe
    Jan 26, 2020 at 16:36
  • Thanks for your help, much appreciated. Though I don't know why some people on this site are down voting the question.
    – SomeUser
    Jan 26, 2020 at 17:37

There are several ways an app developer can prove ownership.

  1. App includes link to web site, web site has name and/or photo of the developer.
  2. Developer can produce portions of the source code. (Trivial for open source, much more difficult otherwise)
  3. Developer can push requested changes to the app. (Again, very unlikely unless it's a small app)
  4. Trust. Developer claims authorship, you believe them unless/until you have reason not to.

For what it's worth, the actual act of putting an app onto an app store typically involves encryption. This means that only the original author (or their delegates) can make changes to the app.

A paper document certifying authorship is pretty much worthless unless it's source code.

  • So you are saying that no need for legal stuff, I just publish to the store?
    – SomeUser
    Jan 26, 2020 at 14:53
  • If the app became popular, and authorities asked me about the app ownership, or maybe someone wants to buy the app later on, what do I show?
    – SomeUser
    Jan 26, 2020 at 14:58

You either are the owner, or you’re not. It only matters if someone else claims to be the owner and complains. Like if I complained to Apple or Google that the app is really mine, then I and you would have both to prove ownership - obviously only one of us can prove it.

If it went to court, it would be best if you had not only the source code, but also for example git repositories for the whole development time. You should have that automatically, but it would be a huge amount of work to forge it.

To the comment: No, everything you write is automatically your copyright (unless you write it as an employee). You don't have to contact any authorities for that or take any action. What I said was that if you developed an app over a year, and you have a git repository that started empty a year ago, and code was added every day, sometimes with bugs, then later with fixes for those bugs, that repository is pretty strong evidence that you wrote the code. And not someone who managed to make a copy of your source code, or not even that.

  • You mean I must copyright the source code of the app, all java classes and xml files?
    – SomeUser
    Jan 26, 2020 at 15:06

Code signing is the only technically guaranteed way to proof your ownership for an app. When you publish an app in Appstore or PlayStore, your app needs to be signed with a developers signing certificate with your private key, name of the company and other related information. All the members who have that private key with them can claim as the owner of the app. For example, Signing process for Android has been described here. Moreover, most of the modern IDEs have the ability to do those kind of signing job for you in implicitly.

Now, when you need to claim for an apps ownership, just extract your certificate from the product and show your information to the person you are proving to.

  • so the private key is found in the developers account?
    – SomeUser
    Jan 26, 2020 at 15:26
  • No. Developer can keep it anywhere he wants privately. Most of the cases in developers PC/storage, i.e. Keychain in case of iOS. @SomeUser Jan 26, 2020 at 15:29
  • Interesting. But code signing does not prove ownership: I could compile and code sign any project if I have the source! The author quality that matters is source code ownership. The problem is then not the signing but the trusted time. A malicious opponent could copy the source, replace the copyright notice, and sign it on a machine with a wrong time that place it before your signature. Management of evidence is a complex issue. Third parties offer this kind of service. Maybe blockchain could be an option as well in the future.
    – Christophe
    Jan 26, 2020 at 22:18

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