This is a nice idea. I remember a similar app on the Market, but I think it disappeared and can't remember its name.
Here are some recommendations:
- Yeah, battery temperature on the same graph would be great !
- It would be much better with "rounded" X-axis labels. Instead of an arbitrary interval between vertical graduations, you should definitely pick the "next-bigger" choice among these: 1 second, 5 seconds, 10 seconds, 30 seconds, 1 minute, 10 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 1 day, etc (I don't know if you need to zoom out more than 1 day per graduation).
- Use "zebra style" background color (for example: alternating between black and dark green for each day).
- I haven't tested your app, but please
ensure that its power consumption impact is negligible Keep up the nice work !