All Android TV devices come with a remote control, but those things do have a way of getting lost in the couch cushions. Luckily, your phone can connect to the TV box and act as a remote. Not as luckily, that can sometimes be buggy. Maybe it'll be a little less so going forward now that the remote service is being updated via the Play Store.
The Android TV Remote Service is distinct from the Android TV Remote app, which is installed on your Android phones and tablets. The Remote Service is what allows you to connect and control the device via Bluetooth. With the app in the Play Store, it should slowly filter out to all Android TV devices as an update to the pre-installed version.
This new version does not appear to come with any enhancements, or at least none Google is telling us about. Feature changes are likely to come via the actual remote control app for phones.