Paid
Ionic
Create cross-platform mobile and desktop apps
Turn Git From a Command Line to a Simple Set of Graphics.
SourceTree is a free Git repository manager that allows users to browse repositories, make commits, and otherwise preform standard Git functions, through a GUI rather than a command line. It works very well for all of Git's standard functions and it is quite fast, but it offers limited "frills" that Git itself does not, compared to alternatives: it cannot be used to directly undo mistakes with one keypress or click, for example.
Pixel art sprite editor
Lightweight IDE software
A Microsoft Development Platform to Install and Run Apps in .NET Framework
The MongoDB Database
Compile Arduino Sketches with Arduino Builder
Build cross platform desktop apps with JavaScript, HTML, and CSS
Twine: Create Non-Linear Stories Easily
Open-source engine for 3D games
Sandbox Free Game Maker: Easy 3D World Design Tool
Solar2D Development Engine Overview
Delta3D Software Overview
Solarus: A Zelda-Style Game Creation Tool