Termux and a BT keyboard it's enough.

Also, native Emacs under FDroid has recently been improved a lot.

With just Emacs you get:

- An IRC, Usenet and Mail client. The ONLY libre Usenet client. comp.arch and comp.misc have really engaging discussions. You can score up nice commenters and blacklist every spammer

- Gemini and Gopher via ELPA (run Esc-x package-install RET elpher)

- A math mini CAS with Esc-x calc RET

- Esc-x package-install RET malyon, get some nice ZMachine text adventures at IFDB

- Elisp environment+cl-lib can do a lot

- Esc-x package-install jabber, Esc-x jabber. Chat with cool people at XMPP servers.

- Org-Mode, enough said

- eshell will allow you to automate stuff

- Elisp + Android related functions + org-mode: heaven.

- Sudoku, Sokoban, Tetris...

- LSP integration it's possible

Get some $10 pocket bluetooth keyboard and try it.