It works! GOSH this took long. I pushed code to https://github.com/staltz/poc-ssb-mobile. There are some crude instructions there on the readme too.

What works:

• Basics: crypto identity generation, "leveldb" storage
• LAN sync from remote sbot to mobile sbot
• Posting feed messages on mobile sbot and viewing that on mobile sbot feed

What works unstable:

• LAN sync from mobile sbot to remote sbot

What does not yet work:

• blobs
• ?