I am reading the Google's doc about LVL.
It is written here : https://developer.android.com/google/play/licensing/overview.html
that "Adding licensing to an application does not affect the way the application functions when run on a device that does not offer Google Play."
Does that mean that if a user uninstalls Google Play (or does not have Google Play, like in China for many users), he will be able to download and use my paid app ?
Thanks.
That sentence is really badly worded. I think what it is trying to say is that you can only use LVL to check if an app was purchased through Play, not to check if it is purchased through any other App store.
If you use LVL in your app, and the app was not acquired by Play, then the LVL call will either fail (if Play is not present) or return a negative result (if Play is present but the user did not buy your app).