Hour Calculator, developed by Thiemeil, is a free Android application designed to help pilots fill in their log books. However, it can be used for various purposes to quickly add or subtract hours and minutes based on figures of any kind. The application offers an easy-to-use interface that allows users to calculate time differences, log book summaries, and find ETA, among other things.

One of the best features of Hour Calculator is that it allows users to enter digits without using a separator. Additionally, the app provides a history of entries and calculations for verification purposes, which is an added convenience. With Hour Calculator, pilots and other users can easily manage their time calculations with a few taps on their mobile devices.