Thanks to helpful feedback from the 100s of daily users, the elves have improved and expanded the MDM calculator.  In particular, they've added a COOL TIMER that you can use to track your time during a visit with the click of a button.  Free and as simple or detailed as you wish.

You can see it all here.  

It's designed to work within a browser or nicely on your phone.  If you want to add an icon for it to your home screen, you can follow these directions.  To be clear, this isn't at all pediatric specific, it's valid for any specialty.