Nobody needs a tuner. I hate them. You can better train your ear by doing it by yourself.
Use your mind.
e
B
G
D
A
E
If you want to make E to a D for example, (Which is tuning it down 2 frets, or 1 full step.) you fret the 7th fret on the E (2 up from the 5 that's used for normal tuning.) Tune the E down til they match pitch.
This tuning is called "Drop D" and it kicks ass. It's used alot in metal. It allows a barr of the fattests 3 to become a power chord.
If you ever get any guitar questions you can ask me. I love helping.
Cory_Long@Bellsouth.net