Simple stopwatch developed with the following goals in mind:

* Extend your device's battery life especially on AMOLED screens (tested on a Nexus 6P; after 30 minutes of usage battery level is still at 100%)
* Free & Open Source (https://github.com/pereorga/BlackChronometer)
* No ads
* No permissions required

Thanks to Josep Balcells for the original idea and testing.