ClipCard for Mac - Instant cloud search with a keystroke on your Mac
Unity - The multiplatform game creation tools for everyone.
Mini Metro - Make the trains run on time
Godot Engine - Feature-packed 2D and 3D open source game engine.
Revisions - A Mac menubar app to view all your dropbox activity
Blender - Blender is the open source, cross platform suite of tools for 3D creation.