I'm new to gaming. I installed Pokemon Go a few days ago on Samsung Galaxy J2 running Android 5.1 with 1GB RAM. Whenever I open it asks for my birthdate and after that it asks to sign in with either my Google Play Account or Pokemon Trainer Club. And as I tap to sign in with my Google Play account it asks that what account to use and just after 1 second it crashes.
However, it works fine on my another phone with Android 4.4 and 1GB RAM.
Best Answer
Extreamly sorry for late reply, I already found the answer months before!
I just went to Settings > Developer options, and switched off "Do not keep activities". That's it!