Creddon - Tweet for a cause and a sponsor will donate $1 to charity
Unity - The multiplatform game creation tools for everyone.
TAP London - Tackling the homeless problem together
Godot Engine - Feature-packed 2D and 3D open source game engine.
UpEffect - Crowdfunding for social good products
Blender - Blender is the open source, cross platform suite of tools for 3D creation.