I’ve been playing around with Corona SDK. I like it – it is simple and robust. It is very easy to make a game and the learning curve is very smooth.
One thing I found myself doing again and again is aligning things next to each other. E.g. putting the player sprite on the ground image, putting 2 buttons next to each other, things like that. It is easy but after some time it gets cumbersome, all those calculations of height and width.
So I created a small library to help with aligning things.