How did google docs app know who I was?

[Schtibbie]

I had google docs app on my iphone but deleted it accidentally. So awhile later I re-downloaded it from the AppStore and fired it up, expecting it would ask me for my google login and password. But it didn't! Well, it did ask me to click on my login name, which it showed on the screen. But then it immediately put me in my files without asking for my password!

Anyone know how this (or any other app) can do this? Did it detect my phone by a unique ID only my phone has? If so, why didn't it at least ask for my password also? Seems kinda hinky.

 

[VTECaddict]

Do you have any other google apps installed? They pretty much all have "single sign on" now so if you sign into one app you're signed into all of them.

 

[Schtibbie]

Do you have any other google apps installed? They pretty much all have "single sign on" now so if you sign into one app you're signed into all of them.

Well yes I do have the gmail app. So... How does that work then? I thought ios apps could not communicate with each other at all! When did that change?

 

[nickprete11]

Because Google knows EVERYYYYYTHHHING