I have built a web application that allows users to login with Google and Facebook through OAuth 2.0. I actually used the SimpleAuth project on Google App Engine. In my database I am storing their OAuth ID, which for Google looks like:
https://www.google.com/accounts/o8/id?id=AItOawnrcuEaKdY_EMesk8FdeFNGP-cCKJbmVf0
and for Facebook looks like:
facebook:1494270173
and I am wondering if I can use the same method on an iOS or Android app. I know that I will need a much different implementation but will that ID be constant even if I am using a Facebook or Google login on mobile?