Owl is an iOS app that, by using data from the Perseus Latin Word Tool, allows a user to lookup any Latin word, locate the root (i.e. the nominative singular for nouns and adjectives or the 1st person singular present active indicative for verbs), and parse the entered form. It gives all possible forms for the word entered. The tool then links the root(s) to the online Lewis & Short dictionary from Perseus, and also from that dictionary, provides links to the works in the Perseus database that are quoted in the dictionary.
I didn’t try it, because I’m not a Mac user, but I thought I’d spread the word 😉