This site looks good. But I wondering if someone has a similar list of apps that are one steps larger than just algorithms - must have UI and be useful.
-- Sudoku verifier
-- library generator (scan all of the music files on your drive and compile a list of artists)
-- dictionary app (using Wordnik API)
-- flexible calculator that can detect postfix v. prefix
-- Sudoku solver
-- Hidato solver (which is essentially King's tour, but cooler)
-- tumblr API wrapper (or really any OAuth service)
-- n-gram language classifier