Stay Put - Unplug Alert

Stay Put helps prevent theft of your device while charging in public spaces.MIT

Suntimes

Sunlight and moonlight times (and alarms)GPL-3.0-or-later

Boilr

Pricealarm for Bitcoin, altcoins, assets & futuresGPL-3.0-or-later

Chrono

Modern and powerful clock, alarms, timer and stopwatch.GPL-3.0-or-later

Napply

Widget for taking quick napsGPL-3.0-only

WaterTracker

reminds you to drink waterGPL-3.0-or-later

Clock31

Clock + Calendar combo widget for AndroidGPL-3.0-only

Keep it up

Simple network monitoringApache-2.0

Mindful Notifier

A mindfulness bell with configurable text notifications, scheduling, and soundGPL-3.0-only

Hisn Elmoslem

You favourite app to azkar.GPL-3.0-only

PhoneTrack

Log positions to Nextcloud PhoneTrack app or any custom serverGPL-3.0-or-later

ShiftCal

Shift CalendarGPL-3.0-only

Keep Alive

Notify others if you haven't used your device in a given period of timeApache-2.0

Anstop

A simple stopwatchGPL-2.0-only

AquaDroid

Reminds you to drink water and tracks your water intake habitGPL-3.0-only

Battery Tool | Hibernate Unused Apps

Automatically stop apps running in the background. Free, no ads and open source.GPL-3.0-only

Smoke Reducer

Track your smoking habitsApache-2.0

Transdroid

Manage BitTorrent clientsGPL-3.0-only

SimpleReminder

Quickly create reminders and get notified laterGPL-3.0-or-later

Skewy - anti eavesdropping

A tool to prevent eavesdropping and ultrasonic access of your smart phone.GPL-3.0-only