Spotify - Map shows when two people play same song at same time

coconutBattery - With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)

Discover on Demand - Just like Spotify's Discover Weekly, but whenever you want.

Accubattery - Monitor's battery capacity through the use of science

Rocketgraph - Rocketgraph is an open-source drop in replacement to Firebase, except it's much better.

GSam Battery Monitor - Monitor your android devices battery usage.