iOS/Android: If your work pays for your car, keeping track of your journeys is essential to avoid potential fringe benefits tax (FBT) issues. Logit is a free app which uses the GPS function on your phone to help track journeys in a format suitable for the ATO.
Logit tracks journey dates and odometer readings, and can be used with more than one vehicle. The kind of records you need varies depending on the method your work uses (operating cost or statutory formula), but using a phone makes more sense than trying to keep paper records.
Fleetcare is a free download for iOS and Android devices. (While it was developed by fleet-tracking service Fleetcare, you don't have to be a customer to use it.)