This is a great start, and very usable already.
First, thank you for putting the community name first, before the poster's name. I'm not sure why all of Lemmy has it the other way around. I usually couldn't care less who the poster is, it's the community name that's important.
Here's my two suggestions: • When viewing a single community and the name is at the top of the screen, there's no need to repeat the "in [community name]" under every post. Omit that and just display the "by [user name]"
• Abbreviate the time display. Instead of "3 hours ago," display "3h". Both Apollo and the lemmy web interface do it that way and it's much cleaner.