I am trying to implement a copy protection (or licensing) mechanism for an android app. The app is not distributed through Google Play or other online market and instead it is distributed through media such as CD/DVD. So we cannot employ market based licensing methods.
The app is a learning app for different levels of education. Students purchase the app media and install the app to their devices (an android tablet) over a USB cable. Students have limited access to Internet so we cannot force them to connect to our servers except one time for app activation over school wireless connectivity.
I know that there is no hack proof mechanism for piracy protection specifically for off-line scenarios and the app price is too low as well as target audiences are students without professional knowledge of hacking or cracking, though my client is willing to protect the app somehow as strong as possible.
I think the mechanism must be something like Machine Locking Scheme but I do not know what the best method is.
Any help or suggestion will be appreciated.