GritUI is designed for an iOS app called Codea, you can learn about it on Codea Official Website.
To solve the problem that I can't create a button, a slider or a switch directly, I created GritUI. It includes a slider, a switch, a pop-up window and something else.
You can just use them like this:
addNewPopAlert("Hello!","Welcome!",true,5)and you have finished.
You can see how to use it in wiki.md.