This is a port of Simon Tatham's Portable Puzzle Collection, a collection of 38 single-player logic games. I used to very much enjoy playing this on PalmOS, so I decided to take it with me when I bought a G1.
Opt in to testing on Google Play.
There's nothing currently in beta, but if you opt in you will receive beta updates as and when they are published.
License: MIT license (same license as upstream). Note that this applies to the source as released on github and excludes the extra graphics in the APK, both on the Play store and here. (This is an attempt to keep the genuine app distinguishable from the clones full of ads.)