WearBright is a one click solution to maximize the brightness of your screen of your android device. The idea is when you are in direct sunlight you can say one command and click the screen to max the brightness of your watch. When you go back indoor you can launch the app again and revert the setting. Note once you change the brightness they will stick, so you can exit the app and the brightness will remain the same.
You can launch WearBright by clicking the screen, scrolling down to start, and choose WearBright. Alternatively you can say "OK Google start Brightness" or "Go Go Gadget Brightness" (A far easier option if you can't see the screen in direct sunlight).
The accompanying phone app currently doesn't do much other then give you one more option to max the screen brightness. In the not to distant future I will add tasker support to change brightness on the fly.