Yes, you can run nostr relay directly on the phone :)
#[1]
Successfully, running nostr-rs-relay (by #[0]) locally on my phone using Termux.

Installation in Termux:
# pkg install rust protobuf
# git clone https://github.com/scsibug/nostr-rs-relay
# cd nostr-rs-relay
# cargo build -r

We can also easily backup and broadcast nostr event using https://nostr-broadcast.pages.dev/ (by #[1])
Yes, you can run nostr relay directly on the phone :)
#[1]
How sir?
That's some guide, you don't see the link into my notes?👆 😅