Unity - The multiplatform game creation tools for everyone.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Godot Engine - Feature-packed 2D and 3D open source game engine.
BuildFire - BuildFire is the easiest way for small businesses to build a mobile app in a matter of minutes for iOS and Android.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
MIT App Inventor - App Inventor is a cloud-based tool, which means you can create apps for phones or tablets right in your web browser.