This feature brings lots of different tools for repository owners to interact with the community. Announcements, polls, labels, different integrations and community insights become available as soon as it is enabled. Recently it went out of beta and now is available for all repositories in the settings menu.
GitHub Discussions is stable now and this how you can enable it.
— 𝚂𝚊𝚊𝚍𝚑 𝙹𝚊𝚠𝚠𝚊𝚍𝚑 (@SaadhJawwadh) August 18, 2021
source:https://t.co/ssj2emtiiY pic.twitter.com/G4dpmhFCpg
In order to give it try on mobile you can either enable it on your repository, either check one of the existing examples.
GitHub - Apps on Google Play
Triage notifications, review, comment, and merge, right from your mobile device