Monetizing app using GPLv3 source code

Question

I need general advice: I have an android app that currently relies heavily on GPLv3 source code. I have never published any app and I'm a bit rusty within android as my day job is programming in a different language.

If I want to publish it as a paid app I can either rewrite the functionality of the GPLv3 code or publish the modified source code - correct me if those are not the options I have.

Is it a bad idea to publish an open source app as a paid app? Could an original author of GPLv3 code license an essentially identical code to me for a fee? An/or is that a stupid thought? Should I just forget "cashing in" or is there another business model to consider? Anything else? Am I just looking at this "all wrong"?

NB: I don't like apps with adds. The model of having a perfectly usable app with an option for a little extra in a pro version (I have also bought pro versions of apps just as a way to donate).

Answer 1

If you are using GPL-licensed code in your app, then it is very difficult to effectively monetize it by asking a payment per copy. The reason for this is that the GPL not only requires that you provide your source code, but also that every user of your app gets the right to re-publish it with or without modification and for any price they want to ask for it, including providing it at no charge at all. This means that anyone can price you out of the market by buying one copy of your app and republishing it for free.

Using ads as a monetization option is also not viable, because under the same GPL rights someone can just modify your app into an ad-free version.

This leaves the options

• Rewrite your app so that you don't use/depend on GPL-licensed code and monetize it anyway you want
• Ask the owner of the GPL code for a different license that doesn't require the disclosure of your sources. This can be tricky if there are multiple copyright holders, as they all have to agree.
• See if you can have a different monetization scheme that is not based on payment for installing the app, but for example is based on using services from a server you control.