Rotorama Laptimer measures drone race laps based on sound level and frequency. Put your phone close to the place where you have start/finish of the track. Set the trigger volume to appropriate level. Default value should work for most cases. If the device doesn't record laps, set the trigger volume lower.
The app is created by Vergilio and its category is Sports. The developer rolled out a new version of the tool on Nov 1, 2019 and over 1K users downloaded and set up Rotorama Laptimer. This application has the overall rating 4.8 on Google Play.
You can download the installer of Rotorama Laptimer 1.0.3 for free and read users' reviews on Droid Informer. The app works fine on Android 4.0.3 and above. The download of the app is safe and secure.