These features have been asked for repeatedly, but no one seems to know that in the last couple of days these new features were added to Connect for Lemmy. So for anyone who was looking for a replacement app that marks as read, or block an entire instance, or filter posts by keywords, you are now able to with Connect!!
PS. The dev @kuro_neko@lemmy.ca recently said the app will soon be open source! Very excited to how the app improves from here!
No where else can you block instances or mark as read after scrolling by a post. I have been keeping up with the updates of all the foss apps, none of them do it.