Ive been learning to program on Android lately and have just put a guitar app on the google market. It shows the chords in the major/minor keys and has chord diagrams viewable by pressing the chord name in the chart.
Its free! Its pretty useful if you struggle to remember what chords are in each key or to remind you of the 12 bar blues progressionss in each key. Give it a try, all im after is some feedback
ive updated this now with working chord diagrams on the minor keys. if you have already got it then update it from the market, otherwise get it on your phone