SamTime is an Android app that keeps track of your appointments either by using a start/stop button or by Bluetooth connections to your car kit. It automatically selects a contact when it detects a contact address is near and adds the appointment to a Google Calendar.
This gives you a minute-to-minute detailed view of where you’ve been. This can be extremely helpful if you’re a freelancer or hourly worker or if you’re just interested in where you’ve spend your day.
Best of all, SamTime is free and available in the Google Play Store.