Disabling or closing soft keys on specific applications

Is it possible to disable or cloae the soft keys on certain applications? I've seen methods of disabling them altogether. While playing certain games they're closed but while playing others they're still on the screen.

XL always open but closing

hi guys
I gave my phone to service last night and brought it last week.motherboard and battery were changed.but when I open the phone several time the message says" phone is shutting down" again and again and power off.I flashed stock firmware but again problem appeared.is it battery or motherboard problem what is your opinion ? thanks and sorry my english:p