Hello. Please check out Presto Metronome http://sourceforge.net/projects/musicstudent/
; a brand new free training metronome that has 3 training modes including: a Accelerando Trainer (that increments the tempo gradually until a goal tempo is reached), a Step Trainer (that increments the tempo by a specified amount over a defined period) and a Scale Trainer that replaces the metronome with any of the 128 instruments available and plays many different scales allowing you to play along by ear. The Scale Trainer works along in combination with the other modes as well which allows you to play faster and with more accuracy.
Presto Metronome is free. For Mac OS X and Windows.
Made by a 3rd year music student (Classical Guitar Major).