Ian Dunn

The <a href="https://wordpress.org/themes/p2" rel="ugc">P2</a> theme lets you quickly create posts from the front end, but by default it only allows you to tag them. This plugin lets adds a dropdown box to the post form so that you can also assign a category to the post.

P2 New Post Categories

Works nicely even on the "Mercury" child theme for P2 :)

Works!

Adds a dropdown menu of categories to the P2 new post form.

Daniel Bachhuber

Easily subscribe to a P2 comment thread without commenting using a “Follow” action link like WordPress.com has.
This plugin requires Jetpack and P2 to both be activated. It doesn’t yet allow you to unfollow, and there are some minor interface quirks.
Happy to receive feedback, questions, feature suggestions, and <a href="https://github.com/danielbachhuber/Jetpack-Follow-Link-for-P2" rel="nofollow ugc">pull requests</a>

Jetpack Follow Link for P2

Easily subscribe to a P2 comment thread without commenting using a "Follow" action link like WordPress.com has

P2 New Post Categories vs Jetpack Follow Link for P2