If you fish out of a boat ,navionics offers lake maps just like the ones they sell for gps units I think they run $15. If you don't have a gps unit on your boat these would come in handy. Another app I like is called the fishermans log pro edition. When you catch a fish you enter it on the log you choose species size and other details or even take a picture of it and it saves it and the program automatically saves your gps location and saves all the weather details of when your catch was made
not a fishing one but shazam its pretty cool. if you hear a song you like but dont know the name or who sings it just hold your phone up to the speaker and hit the button and it will tell you who it is and the song and the album. pretty cool app.