Gadgetbridge - A free and cloudless replacement for your gadget vendors' closed source Android applications.
Splittable - Shared living made simple
fitbit - The Fitbit mobile app is for people who use Fitbit fitness trackers to keep track of their activity goals, food plans, and other fitness related things. Read more about fitbit.
/Tab - The simple way to split a bill among friends.
Strava - The #1 app for runners and cyclists
Splitwise - Splitwise is a free tool for friends and roommates to track bills and other shared expenses, so that everyone gets paid back. On the web, iPhone, and Android!