When logging time in your logbook you can define the features of the aircraft that you are flying. This assists with tracking things such as tailwheel time, turbine time and so forth which may be useful for insurance, career progression, etc.
As you enter the details for your log entry, click the “Others” tab and enter the details for the aircraft you are flying. In the web version the interface appears like this:
For the app, you will see the following:
This information only needs to be entered once. For future entries, lockr.aero will remember the aircraft features and automatically populate these details after you enter the aircraft registration details.