[pc86]

That's a really good idea. I could see a small Arduino board with wifi and a FlexiForce[0] (just the first thing that came up in Google for "Arduino weight sensor"), and like you said a mobile component that would either be a stopwatch to actually log or a time entry for past movements (or when you didn't have your phone, etc).

My sister has Crohn's and one of college roommates had UC so I'm somewhat familiar with it.

My contact info is in my profile if you want to talk about this more.

[0] http://bildr.org/2012/11/flexiforce-arduino/