Hi,
I am currently working on a game that has rewards for completing achievements (in the form of redeemable codes, vouchers for ISPs/online shopping and such).
There will be a web server for it but I need to do as much app-side as possible. They want to avoid having to add a user login system to the website.
I was thinking I can get the device ID and then send the device ID, country and achievement ID to the server when achievements are completed, which checks if anything is available and sends the reward back if applicable.
But this means changing device but not playstore account will get you all the rewards again (if you finish the achievement again).
Is there a way to check both the DeviceID and the playstore account without the game having you logging into external servers? Playstore account only should work as well.
I feel like there is a simpler built-in solution I am missing, I have no experience with apps that need to go online.
Any help is greatly appreciated!