Should I turn off iCloud syncing in this case?

The user of my app can buy “golds” in my app and I save the gold number into a file.

So should I turn off iCloud syncing in this case?

I mean, if the user buys some gold, and backup, use a lot of gold to play and then restore, then he can keep using the gold?

Personally I think you don’t need to bother thinking about that. 

Firstly, there are always people who’ll try to cheat the system and there’s no way to prevent that from happening. I just don’t think these people are worth the effort it takes. It’s better to spend that time on creating a great game instead.

Secondly, there’s no way to restore a single app. They’ll need to restore the whole device. This means that they’ll lose all other data in every other app just to get some extra game gold in a single app. 

Personally I think you don’t need to bother thinking about that. 

Firstly, there are always people who’ll try to cheat the system and there’s no way to prevent that from happening. I just don’t think these people are worth the effort it takes. It’s better to spend that time on creating a great game instead.

Secondly, there’s no way to restore a single app. They’ll need to restore the whole device. This means that they’ll lose all other data in every other app just to get some extra game gold in a single app.