Sken.io - The most advanced tools for tracking changes on websites.
Invision - Prototyping and collaboration for design teams
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Dotarchy - Pick a topic, discuss it, make some Friends
Finch for Windows - Make visual changes to any website. Immediately.
Start on Android by Google - Developer program to optimize your app before you launch