When storing information about users, would two autonomous apps identify the user by the same id in each respective database?
I install app_1 in my iPhone, how is my user id created in app_1's user db?
Then I install app_2, would the iPhone use the same user id?
Or does the user id completely depends on how it was programmed on each app?
What if those apps use social networks to allow me to sign-in? and I use facebook in both?