Ismail

Does the same functionality as BuddyPress, emailing users who get mentioned in a bbPress topic or reply. The aim of this plugin is when to enable that feature when no BuddyPress is there. 
To do: – warn user about bbPress/BuddyPress presence

bbPress Mentions Email Notifications

Adds the @mentions to bbpress - really useful

Great plugin

Email bbPress topic/reply mentioned users, set custom email and some basic settings

rizwanchaudhry

BCS Website Solutions

Allow users to login with either Email Address or Username.
Just install the Plugin, no coding experience required.

Login with Username or Email

This plugin inserts a dozen of ads, including graphics, very prominently into the user interface.
Worse, every user can dismiss every single of these messages (separately) and the plugin makes sure to remember this "setting" for every user as a meta value - polluting your database with senseless garbage.
Lastly, the plugin enures not to include an uninstall action hook, so you need to manually clean up this mess.
Well done.  That's how to promote your business.  NOT.



Beware: Scam

Allow users to login with Email or Username while logging in to Wordpress.

bbPress Mentions Email Notifications vs Login with Username or Email