I have a similar question -
Say I want to reward players for playing my game every day. On day #1 I give them 5 coins, on day #2 I give 10 coins and so on.
I guess some users may try to cheat this system by changing the date on their phone.
Should I bother trying to prevent this, maybe checking some Internet clock server?
you can prevent that by saving the users current date and time off closing the app or logged in the app and approximate the time when he logs back in, if he comes after 30 minutes with date saying 1 days later ur server should compare actual passed time and not reward nothing. thats should be a relative easy time exploit patch to do with a bit of sql database and C2.
but what the OP said was a bit more difficult, cause he was talking about the API of 3rd parties and stuff... which usually are pretty secure, unless they have some bug in a version and leave open a security issue in your app, and you cant do nothing about it unless you update the api to the next version that is patched or older one that doesn't have the issue, with the risk of loosing some of the features in your app.
sorry for zombifying the post. read to late the date .... of initial poster...