by Prasanna Moholkar
Update: for those who wanted it multi app, here it goes: http://llamalab.com/automate/community/flows/3552
For those like me who enjoy checking photos with higher brightness, this is for you. When using Google Photos, it'll set brightness to the level you define at the beginning. As soon as you close Photos (or send it to background), it'll set brightness to the level you had before, either fixed value or auto.