Closed beta, first wave
The server is up and the Android build is on the download page behind a Groot ID. No end date: this wave runs until the next build is ready.
This wave is narrow in what it tests rather than in who can join it. Its job is to find the failures that only appear when a real device on a real network talks to a server that has never had one, and for that it wants variety of hardware more than it wants a queue.
How to join: sign in with a Groot ID and take the build from the download page. There is no invitation to wait for and pre-registering is not a requirement.
What to expect: sign-in works, an account is created and kept, and the game receives all of its data. Battles, summoning and deck editing are not in this build, and reaching for them can end the session until the next update lands. Every device is handed the same guest account, so treat the save as shared and anything in it as scratch.
What to send back: what you did, what happened, and what you expected instead. Device model and Android version help most, because the failures worth catching at this stage are usually specific to one of them.
The wave has no closing date. It ends when the next build is ready to take its place, and that is announced here.