Yes — on Google Play
R4 Companion has a Google Play listing.
App Store
On Google Play
Is R4 Companion on Android?
About R4 Companion
NOTE: R4 Companion™ requires a Uniden R4 or R4w radar detector with US Version 139 (R4) or 122 (R4w) firmware to function correctly. R4 Companion will NOT function correctly without at least this version of firmware. R4 Companion™ is a feature rich app, designed to give you the most out of your R4, while enhancin…
R4 Companion is listed on both the App Store and Google Play from Angela Mcarthur, so you can install it on Android phones and tablets. The Play Store listing shows 10,000+ installs.