The upcoming v1.2 release will include a built-in instance chooser, so every instance will be able to recommend every other instance, without a centralized site like https://joinmastodon.org/ or https://lemmyverse.net/instances. (except those instances that have opted out or closed registrations)
The instance-choosers for other platforms tend to push people towards the bigger instances by prominently displaying the number of users or communities they have, or even worse sorting results by number of users. This seems like a good metric because if lots of people chose it in the past then it must be well-run, right? Right? Heh.
Instead, the PieFed instance chooser sorts by ping (network ping + page load speed) and prominently shows a "Stability" metric which is a combination of various things (daily backups, multiple people having SSH access, financial health, etc). Another key metric is Newbie-friendliness which is whether they have a decent number of topics created, which are used as starter-packs to get new accounts into many communities quickly. Thirdly, the Age is shown, which is the number of months it has been operating. Join brand new instances at your peril.
Another aspect I've chosen not to get into is regional or topic focus of instances because most people are into more than one topic, leading to difficult choices. Sorting by ping will tend to show you instances in your country anyway.
The primary language of an instance is really important - people need to be able to communicate with their admins - so I made that a filter.
With new PieFed instances opening up all the time we need to get new people using those instead of everyone clustering together on piefed.social. The sooner we do this the better, in terms of spreading the financial load around and fostering a healthy diversity of instances before one or two instances snowball and end up dominating.
I'm really looking forward to releasing this functionality, in the next couple of weeks.

Hum, seems like it's been hanging for a few months now, pending on F-droid
https://gitlab.com/fdroid/rfp/-/issues/3053
If you consider Obtainium: https://github.com/idunnololz/summit-for-lemmy
F-Droid takes awhile to accept new apps. I can only speak for the one app I submitted to them, but it took almost a month for my pr to get merged.
After getting merged, updates won’t appear on F-Droid for 3-6 days. That’s because F-Droid has a roughly 3 day build cycle. Depending on where they’re at in their build cycle it’s 3 days best case and 6 days worse case.
This isn’t a knock against F-Droid. Just by their transparent nature builds will lag a little.
Thank you for your insight!