The new M7 coprocessor in the iPhone 5S makes pedometer apps trivial:
[code lang="csharp"]
if(CMStepCounter.IsStepCountingAvailable)
{
var counter = new CMStepCounter();
//Last 8 hours
counter.QueryStepCount(NSDate.FromTimeIntervalSinceNow(-8 * 60 * 60), NSDate.Now, NSOperationQueue.CurrentQueue, StepQueryHandler);
}
void StepQueryHandler(int nssteps, NSError error)
{
Console.WriteLine(nssteps);
}
[/code]