This exercise was the first fingering exercise my bass teacher taught me so this exercise is good for bass players as well. It accomplishes a few things.
1. Builds finger dexterity.
2. Builds finger strength.
3. Improve your sense of time by playing along with a metronome.
4. Should increase your finger callus.
Place your thumb behind the neck so that it is perpendicular to the neck of the guitar (pointing up). Try to place your fingers as close to the back of the fret for less fret buzz and for less resistance. Perform this exercise forward and reverse in single time then in double time then move up the fret board one fret at a time all the way up as far as you can go.
I set the metronome to 80 but you can use any speed you like. 
Oh yeah, and yes that’s a free metronome app for the iPhone.
