Google drive allow to store data and share it between devices. But I want to store user's photos in this. I can't find any information about limits at Storing Application Data web page.
So. Any info about size limit of Google Drive's App Data Folder?
from the same docs--
Despite being hidden from the user, the App Folder is stored on the user's Drive and therefore uses the user's Drive storage quota.
so it's same as much as space available for user in his google drive account.