VoltSim - VoltSim is an interactive realtime circuit simulator. It has digital and analog components and even Integrated Circuits. It is the perfect companion to students, hobbyists, and engineers.

Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.

Diode - diode - Android app to interact with reddit.

Eduflow - Digital learning that actually teaches students something

Circuit Stickers - Peel-and-stick electronics for crafting circuits.

Backchannel Chat - Backchannel Chat is best in class discussion tool that is intended for teachers to streamline their class activities.