RazielKanos

This plguin simply adds a CSS code into your Admin Dashboard and hides most of the nagging messages telling you 
that you should activate or register other GPL 2 Plugins.
It doesn’t add any functions other than adding the CSS code, so there should be no trouble with other plugins you are using.

WP Remove Admin Register Nag

This plugin removes the reminders that you should register plugins you got by a theme for example

BlashO

Tired of manually cleaning all those spam comments from your blog? You don’t need to work manually anymore. Install this plugin and just schedule – it works for you.
WPSpamComments works in 2 different modes:
Manual Mode: Where you can click “Delete All Spam Comments Now” to remove all the spam comments from your blog immediately.
Auto Mode: Where you have to configure the periodicity (in hours) and click “Schedule Now”. The plugin periodically cleans all the spam comments from your blog automatically.
Go and enjoy blogging, don’t worry about spam comments anymore.
<a href="https://www.blasho.com/wp-spam-comments-plugin/" rel="nofollow ugc">More information from plugin page</a> 
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WP Spam Comments from BlashO

Automatically delete and clean all the spam comments from your blog. Just schedule it once.

WP Remove Admin Register Nag vs WP Spam Comments from BlashO