how to delete the apps all data? I have an app that give you points if you share your link and someone download it so I send the link to my sister to download it but I didn't get any point then I found out that my sister has downloaded it from a long time but she deleted it I tried to delete it from the storage in the settings and download it again  but still I cant get points , do you have any idea how to completely delete an app ?

sorry for my bad English ^___^
Most apps like that do the registration server side and you would need To erase the device entirely and not use the same Game Center account. 

Deleting the app does delete all data unless it’s designed specially and in that case, you need to know exactly what bundle and delete the data from iCloud on a mac, not from iOS. 

In general, deleting the app deletes all data. Especially if you don’t enable iCloud.