Send score through email in apk application

Hello,

I would like to make an apk application for my students. I want to know the score they got in the games i made. And to be sure they don't give me a fake result, i need the process to be automatic so i thought about either sending some kind of password or hash for a certain amounts of points but i didn't manage to do it,or do something automatic they wouldn't even notice.
As they are all permanently connected to the internet on their phones, i thought i should probably make something like a screen capture and send an email with the picture as an attachment OR i i could just get the current score, copy it and paste it as a body of the email and then send it automatically.

Is that even possible ? If so, what would be the best solution ? And how to do these things please ?

Thanks in advance.

StingRay : Thanks for the reply. I'm a noob. I tried to add mySQL and PHP database on the ftp account of my website to make a test, i configure like i saw it in the tutorial but it failed and i don't know why. I just wanted something easy for people like me who don't have much knowledge.

Anyone else has another idea please ? Or could explain this idea a way someone like me can understand and do easily ?