Tech writer Michael Thomsen has a piece in Complex Tech about a new iPhone app that "wants to make you a better lover." Inevitably named Spreadsheets, it uses your phone's accelerometer and microphone to measure how, umm, active and nosiy one is in bed. Leaving aside the question of how useful volume is as a measure of satisfaction ("Oh yes Yes YES" and "watch the hair OWW!" are equivalent if they're said at 80 decibels), Thomsen notes a more general objection to apps like these:
when we depend on apps for advice about self-improvement, we are always dooming ourselves to remain in the present, marginally changed on a personal level, paid for by deferring consideration of just how many different options there are communally. And in that way we come to serve, not our little devices, but the powers that brought them into being, blaming our feet for the potholes in the road.
Put another way, the apparent neutrality and objectivity of measurement hides a whole world of decisions about what should be measured, and what counts as improvement, not to mention what defines "self."