iGodot
Last fall, I realized you could compile the Godot game engine to run on the iPad. This presented exciting possibilities, combining two of my loves: the Godot open-source project, and the iPad operating system.
And while Godot can run on the iPad with minimal effort, it remains essentially a desktop application that runs on the iPad, with the downsides that one can expect from it.
The Godot user interface has been optimized and tuned for developers on desktop computers with access to a mouse.