I would like to secure my app from beeing hacked (at least a bit). I would like to check some things online to prevent a not allowed (let's say not wanted 
) user to use my app.
Is there a way to get a checksum of my app plus check the sign key in some way online (by transmitting it to a server)?
) user to use my app.Is there a way to get a checksum of my app plus check the sign key in some way online (by transmitting it to a server)?
