A Time Calculator is available just below the Out/Takeoff/Land/In fields (if optioned to show) and also on the bottom of the Home Screen. The Time Calculator is used by pilots that fly multiple legs in a day and want to enter the information as one flight log entry by calculating a total duration for multiple start/end intervals. Enter the start and end "time" in 24HR format such as 1400 and 1535. The times must be in the same time zone, i.e. UTC if you fly across time zones. Once a start and end time are entered tap "Add Interval" to add the block time and calculate a duration for the leg and add it to the total duration shown at the top in blue. You can delete an individual row by long pressing an item and then choosing the delete option. Tap Clear if you want to clear the entered values and start over.
An HH:MM presentation is provided for reference only which is the exact hours and minutes between the start and end and then a grand total HH:MM is presented on the top of the interval listing for those that want to use the Time Calculator to calculate HH:MM info.
The Time Calculator can be hidden in Settings/Flight Log Layout if it is not something you would use and you can further cleanup the display to only show what you need. Tap "Copy" on the bottom to copy the decimal duration value to the device's memory (clipboard) which can then be pasted into a text field by long pressing and then selecting Paste.
Each flight log entry uses its own individual time calculator data so you can log the legs associated to that flight. The Home Screen is also isolated from flight time calcs for general purpose use.