i am on way to making game. and i am trying to solve an issue about time.
gamer get life (when all rights of playing finished) every ten minutes. (at the same time i will sell a life as an in-app like candy crush). game is offline playable. i am getting time and save it when user killing app . When he/she opens game getting current time and giving life by making date subtraction. here is an issue that;
when user kills app, adjust time to 1 hour later and opens the game again (problem goes and i am giving lifes).
is there any way to solve this problem. is there any time source (without online access) that user can not change and i can retrieve correct time.
ps: i will code the game in iOS environment. iOS specific answers will be appreciated.