The ‘in-app purchases’ text is somewhat misleading, as the ‘charge for the app entirely up front’ thing is more like how this actually works. The option to purchase the full version is just moved in-game, instead of listing two versions Google Play, a free one (not containing all the ‘activities’) and a non-free one (with all activities).

And if you prefer not to support further development of the app financially, and stay with the limited version (which still have about three dozen fully working activities, mind you), you can hide all the non-free activities from the game from the preferences menu. There will be no nagging from the game to purchase the full version.

I agree that the description in the blurb is quite vague. But a picture speaks more than a thousand words, and I think a video is even better, so here’s a three-minute video showing GCompris in action (it’s the same video that you get when you click the video link on the Google Play page). It doesn’t show all (currently 88) different games/activities in GCompris, but it should give you a pretty good idea about what the software is about.

No worries. I’m happy to tell you that all of GCompris, each and every activity, is free software. If you download the source code, you get the source code for all the activities.

If you want to, you can compile the software yourself. (Actually, there’s not much compiling required. GCompris Qt is written in Qt Quick, so it’s mostly just JavaScript code, that doesn’t need any compiling.) You can get the latest version of the source code at the KDE Git repository, or at a GitHub mirror.

The linked release notes mentions that GCompris is fully translated into 8 languages. But note that it’s also partially translated into (currently) 29 languages. In fact, some of the languages supported don’t even exist as native locales on the Android platform (but you can still choose the language manually, in the GCompris preferences menu).

GCompris was only very recently moved to the KDE infrastructure, and it’s still in the review phase (see the KDE software lifecycle), so not all translation teams have started translating it yet. But hopefully, many more languages will be fully supported in the future. Note that ‘fully supported’ also means custom word lists for each language (for the reading practice activities), and even voice sound files for some of the activities.

I think good language support is very important for educational software like GCompris. And the number of languages (partially or fully) supported shows the power of free software and the free software community. The software can (and will) be translated into smaller languages that are not commercially viable for proprietary software. (Full disclosure: I have been translating GCompris to my native language for a number of years.)

The software is licensed under the GNU GPL 3, and is thus certainly free software. It follows all four freedoms in the free software definition. It is also open source, under the offical Open Source Definition. In fact, being able to sell the software is integral to it being free software. From the GNU licence FAQ:

And, of course, the source for GCompris Qt is available, at both a KDE Git repository and a GitHub mirror. You’re welcome to compile it yourself, and play it for free, on either a Linux system or an Android system (or any other system you wish to port it to).