Zeplin - Collaboration app for UI designers & frontend developers
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.
Abstract - A secure, version-controlled hub for your design files
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.