You must have Xposed framework installed in order for this app to work.
Jit Screen On is a cool Xposed mod that lets you select specific apps for which the screen will stay turned on as long as the app is in the foreground.
☆ Select whether screen stays on for selected apps as long as the app is active or set a timeout after which the screen will turn off
☆ Does not use wakelocks
☆ Does not change system settings
This is a fully functional 30-days trial version.
After 30 days the app will be disabled until installing Jit Screen On License from https://play.google.com/store/apps/details?id=com.Taptigo.Xposed.JitScreenOn.License