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.
Join the beta group and follow the instructions there.
There's nothing currently in beta, but if you enable notifications for the beta group you'l know when there is something.
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.)