This Old Neon Forum

TypeShift is a free game by Zach Gage (who also did SpellTower, if you follow word games at all). It's kind of like an anagram finder meets a crossword puzzle. You move each letter in a puzzle up and down to create words across the middle row. It's a pretty nice little time killer for a word nerd like me.

Caveat: it is supported by ad-pestering, but one purchase of any of its level add-on packs removes ads and also unlocks a couple other options (stats, skins, etc.). The cheapest add-on is $1.39 for 60 puzzles, and there are many such packs (there are a lot of free puzzles, too, so don't worry that you'll only get a handful of tutorial puzzles for free).

Hmm, not on Android yet, from the looks of things. Spelltower was a [goes on to talk about a totally different game], I'll keep an eye out for an Android port.