User blog comment:Alb3rtusja/About Daily Quest & Weekly Quest/@comment-5957202-20161115023616/@comment-26432452-20161115063757

The left button is clear game data, use it if the game bugging out IIRC. It will keep your account but ofc,don't use it if the game works normally.

The right one is the account transfer window. Use it if you want to load your account on a new device.