To participate the beta program, you need to opt-in from the following links:

Free version: https://play.google.com/apps/testing/com.racechrono.app
Pro version: https://play.google.com/apps/testing/com.racechrono.pro

After opting in you get the latest beta version through Play Store update. Once you’ve tested the beta and have insight or problems, please post your feedback here:

https://racechrono.com/forum/discussion/1701/android-beta-feedback-thread