Not sure if this is already known, but if you're like me and have Android and want Musicboss, Autoapp, etc on your shiny new watch, and have no patience, use Micropebble instead.
Install the new Pebble app, do the setup as usual. This will ensure firmware is installed.
Remove watch from bluetooth.
Install Micropebble.
https://github.com/matejdro/microPebble/releases
Connect.
Disconnect watch in Pebble app (if you leave it connected it will do strange things like install apps from both services)
Install your apps from .pbw files
https://apps.rebble.io/en_US/watchapps?dev_settings=true
(This link exposes .pbw downloads for each app)
So far most of my apps work. Voicenote is a nogo. The old version of Nav works, as does Music Boss,
and Autopebble (The most important)