My top metronome pick, which combines both features and accuracy, is Metronome TS (V. 1.31, Thezi Studios; $3.99). It provides visual (a virtual baton) and aural reference (with a choice of tones), multiple selectable rhythms, tap-tempo, and more. A free alternative is Metronome-iTick (V. 1.3, Music Motion), which has a digital-style visual display, adjustable time signatures, and user-changeable sounds.

FEATURES, AT A GLANCE

Tap tempo
30 to 250 bpm range
0 to 19 beats per bar
Nine selectable rhythms
Four selectable voices
Ability to play clicks through the first-generation iPod Touch's internal speaker
A440 reference tone
Italian tempo markings
Auto-lock disabling
Ability to save and categorize tempos

Find out more information about Metronome TS.