What are your must-have top features you’d want to see in a Lemmy app or web client?

Order comments by hot/new/votes
make it really obvious how to sign-up and sign-in
linking between feddit should not open an in-app browser
highlight comments/posts your account has made
allow us to block all NSFW posts from the all feed
allow us to post GIFs from the Google keyboard

I'm mostly waiting for marking posts as read as you scroll by and hiding read posts (but only in your feed). I think this is especially important with the federated content that might come in later than when I "scrolled past" the point in time it would appear in my feed.

"come in later"? You want a feed that live updates?
- They probably mean that you can't just scroll through and say "okay, I have seen everything created up to the point when I loaded this page" because some posts created earlier might only appear in your feed later.
- No.
  
  But say, I'm currently looking at my Subscriptions sorted by New. I doomscroll until I see stuff that is 10 hours old. While I do that posts could come in that are 5 hours old. But the next time I doomscroll I wouldn't go that far back because I think I've already seen stuff that old.
  
  If what I have seen already was automatically marked as read and not showing for me, I would still see the 5 hours old stuff because that wouldn't have been marked as read.

Being able to jump back a page without snapping to the top is the only issue I have with the PWA set up I’ve got. Otherwise it’s great as is.

Honestly, Memmy works pretty amazingly… I was surprised, because last time I tried it it was… empty. It’s REALLY good now.

For web: better theming, for app: i18n, for both: much smoother subscription to other instances.

I haven't seen anyone mention this yet, but the biggest feature for me would be an automatic redirect to your current instance if you click on a fedi link to another instance

It's annoying when someone links a post from another instance, and I click the link but I can't interact since I'm not logged in on that URL

Basically, if you're on one instance and click on a link to a post from another instance, it should open that post on your current instance. The desktop version of Lemmy needs this too.

This is really my biggest point of contention with the fediverse atm. Needs to be easier to interact across instances without copying, pasting, editing, or typing in URLs

Permanently Deleted

keyword filters, so you can avoid posts about "trump" or "hitler" and other things that annoy you

Connect has this

Subscribe to whole instances, not just individual communities, that are not Federated by the instance my account is logged into.
Easily block communities from the ALL feed, without 3 or 4 clicks

, that are not Federated by the instance my account is logged into.

How do you imagine that would work? Federation is what enables you to interact with anything on other instances in the first place.

Or do you just mean "add all communities on a remote instance to the list of communities you can search for locally at once"?
For point two, Connect for Lemmy just added a block button from the three dot menu on the feed.

Multi-lemmy. I really miss having my custom feeds made with the multi reddit tool,.

This would be so useful to group related communities from different instances as well.

User option to block Lemmy server/instance

Ability for a user to essentially block an entire servers posts. I don’t want to rely on my admin to block a server. I want the option to block all posts and the option to block all posts and comments. (Block or hide is fine)

Quick Scroll

Button to scroll to next top comment that can be held to scroll to previous top comment (like apollo has)

Mute words

Ability to block/mute words so for example i can block all communities with the word meme in it because i want to browse All to find new communities but i never want to see meme communities/posts.

Notes

Add custom notes/tags to a user/community that can be color coded

Embed youtube/invidious/peertube that pins on scroll

When opening a thread with a link to a youtube/peertube/inividious link have it embed and play in the app and when you go to the comments have the video stay pinned on top so you can keep watching while scrolling through the comments

I'd like some tablet/large screen optimizations now that I have a Pixel Fold! Sync for Reddit and Infinity are example apps that do it right in my opinion

The ability to copy the URL of a video so I can paste it to NewPipe - or a setting where I can choose to use YouTube or NewPipe all red the time.

Off the top of my head…

Easy user following
Auto markdown
Download image/video
Share as image

wefwef.app is perfect and extremely smooth right now and can be installed locally as an app. It's open-source, it has a GitHub repo for those who want to host their own or want to audit the code. Would be cool if it was available directly as an apk on Play Store, I believe it would be hugely beneficial for Lemmy if it became the "official" app!

I'd say other apps should try to take some hints from wefwef, it does all the things right, is inspired by Apollo and once you use it you won't miss Reddit at all!

Swiping in order to upvote/downvotes/reply is an awesome feature that definitely stands out.
- I'm not a fan of gestures for actions in general, I spend a lot of time trying to get them right or even worse, accidentally making them and doing something I didn't want.

Favourite communities (to appear on top of the list);
Better video support;
Better sorting algorithm;
Search for posts (most apps still don't support);

On top of that, I think the most crucial is to have a very fluid and stable interface, which I think is not the case for most apps.

Before I got thunder I used jerboa. It has a bug where when I backspaced it would squish the text together making me have to go and respace my text.

Ability to choose the default sort for comments

Apart from the ones already mentioned,

being able to collapse all threads in a post to only show parent-level comments
keyboard shortcuts ala RES (esp the J-K navigation)
more themes (the default ones suck)
more image improvements

For your 2nd point, I made a script. It works with arrows so you may or may not like it. Also I see a PR was opened yesterday on Lemmy-ui for J-K navigation

Honestly I just love it and I hope it keeps growing

Sometimes using jerboa to open images doesn't quite work the way you'd expect it to, and I know that's not really Lemmy as such but it's about the only negative I can think of

Something similar to what Infinity for shitdit had, we definitely need usability tweaks and better customization options, it would also be great to have different appearance settings per user and nsfw blur per user as well.

I'd love if there was a way to categorize saved posts for both account and local storage and the ability to choose to save posts to a local storage list.

Being able to add the Dracula theme. That's it, I miss it from Infinity </3

Massive effort on high quality i18n, l10n and a11y.

Improving just these will make Lemmy accessible to millions of more users and communities.

Favourite communities (to appear on top of the list);
Better video support;
Better sorting algorithm;
Search for posts (most apps still don't support);

Something very simple on the web client: a setting to get links to open in a new tab, to make it easier to get back to the same point in the comments.

An option to merge the same post from two different communities in a way that preserves some semblance of federation while also making it so the same headline doesn't appear a half dozen times in my feed. Maybe by merging together comment sections and putting an indicator next to each comment chain showing which instance it came from.

Something like Reddits "other discussions" button would be enough for me, just pop up to a list of other posts of the same link and list how many comments in each so I know which ones to click on.

A wishlist for two categories, in each sorted from very important to less important:

Technical:

Open all links relative to my home instance (I want to stay logged in)
Make community discovery easier and consistent. One method, which always works.
Move account to another instance, complete with subscriptions and notifications when older comments receive replies
Clarity: I'm often confused in which community a post lives, or where it originated. Or what a user's home instance is. It is fine to display relative information (Post X from instance Y as seen from instance Z), if clearly less emphasized
Indicate who can see a post or comment. From what instances is that content visible?
Display the same community stats regardless from which subscribed instance they are viewed (subscriber count varies wildly)

View:

Allow to hide selected posts
Expand and collapse images in threads
Lock my feed: Please don't add posts to the top while I'm browsing the thumbnails at the bottom
Display post/comment live preview below input field, so I can see the preview while editing. Currently I must switch view.
Search within a community (without leaving the community page)
Customize your feed: Control how much of each community is displayed (I want posts from some small communities to always show, and posts from others to only show rarely, or only those with votes/comments)

This was meant with the web/browser in mind. I expect apps and clients to work similarly, unless a characteristic necessitates exceptions (screen size, touch, ...).

I want the ability to login to any given Lemmy instance with another instance's account. Kind of like how I can login to various sites using a Google account. I think it would be fantastic if I could login to say, Beehaw.org with my Programming.dev account. That way if I'm perusing Beehaw.org directly I don't have to worry about having my own account there or finding that community back at Programming.dev (and waiting for the subscription to update); I can just login with an existing Lemmy account from some other instance.

If a Lemmy instance is already federating with an instance where I have an account I don't see any reason why this would cause content/moderation problems.