RE: can not sign in and open the coin pop app
I have no idea what's going on in this report.
First, the app you fail to open is coin pop, some scam android game:
https://play.google.com/store/apps/details?id=company.coinpop.coinpop&hl=en_US
Second, the repo you link is of some altcoin that will go ICO in a month or so:
https://github.com/Pop-Currency-Foundation/PopularCoin
It has nothing to do with the game you can't open, and it doesn't have android client.
Beyond that, let's say coin pop was a valid open source project... It doesn't work at all on your device. This isn't crash, this is the code not doing anything. At most it runs in the BG and acts as a keylogger, which is probably what it was intended to do. App the doesn't start on your device is not the app crashing. It's like reporting a bug for android app not working on iOS.