If you can use Termux, you can use the command-line lftp, which supports SFTP; I use this on Linux, so I’m familiar with it.
$ pkg install lftp
$ lftp sftp://foo.com
I also use rsync in Termux after being exasperated over the lack of a reasonable F-Droid graphical client for that.
I wound up using some non-open-source graphical SCP or SFTP client out of the Google Play Store using Aurora Store’s anonymous login at one point, which worked but wasn’t what I wanted to use.





























I’ve seen a variety of people running stats dashboards of various sorts. Some spring up, others go down. A couple:
https://lemmy.fediverse.observer/stats
https://piefed.fediverse.observer/stats
https://lestat.org/ doesn’t have all instances, but can be a useful dashboard for major instances.
EDIT: Lemmyverse.net walks the Threadiverse to update its index and gathers various interesting types of information:
https://lemmyverse.net/inspect
https://lemmyverse.net/inspect/version-chart
They also let you download their data, if you want to do your own analysis.
EDIT2: https://fedidb.com/