The main game of Sidewords is a reasonable puzzle. I played a bunch of them up to the "spicy" 6x6s and enjoyed it. I'm not sure there's much to keep me coming back -- it seems like one puzzle can't be cleverer or more devious than another, because there are so many solutions to each puzzle and there kind of have to be. It seems like more constraints would help.

Quads is great! I can tell it wants to be a mobile game and I'll probably be getting it on my phone. It reminds me very much of Threes. I had the serendipitous experience in my first game of thinking I was stuck, then forming one word to make a combo of 6 exploding quads, when I didn't even realize combos were a thing.

So Quads is actually the one that would keep me coming back.