Puzzle Sidekick — Reference — Free
Puzzle Sidekick is an ambitious app that hopes to serve as a reference guide for people who do crosswords, augmented-reality games, puzzle-driven scavenger hunts, and whichever other situations one might need a working knowledge of semaphore.
It also contains guides to codemaking (and breaking), information on our solar system, and a couple dozen other random topics that I can’t even remember right now. So even if you’re not following a puzzle trail anytime soon, it’s still an interesting collection of random information that’s worth a look.
