1.1
+ auto start front flashlight
+ show 5s countdown number for back button
+ fix resuming exception
1.0
+ Change app name to "Twin Flashlights"
+ Build from scratch with twin concept
From Screen Flashlight to Twin Flashlights.
Open both front and back flashlight at the same time.
For back button,
I make a 5 seconds delay per click,
to take care of physical camera flash.