Now I'm not someone normally associated with technical computery things (what's wrong with a big bit of slate and a piece of chalk?) but apparently you can get the "Bike Doctor 2" app free for a limited time
According to the blurb "Bike Doctor 2 has been created to make bicycle maintenance incredibly simple".
I haven't tried it, I don't know whether it's any good but it's free so you could download it for nothing and then delete it if it's rubbish (download / delete - get me with the technical terminology!)
