Plugins can only be used on hosted sites: here are a few

Ad Rotate: This provides a “rotating” call to action in the information column of the blog. The people who visit your blog are likely to be interested in other things than you. This puts multiple calls to action in one small space.

Akismet: This is a comment spam blocking WordPress plugin and absolutely essential for any blogger.

 BackWPup: This makes sure your blog is backed up without having to think about it and can be scheduled and also saved on to another external server apart from your website hosting provider.

Floating Social Bar: Floating Social Bar is unique in the world of a ton of social share buttons: They stick to the top of your screen as you scroll down. While there are similar ones that work on the sidebar, these sidebar social share plugins aren’t visible on all mobile devices.

Google+ Blog: This plug in allows you to send posts from Google+ to your WordPress blog by adding a hashtag to the post.

Leadpages: GREAT plugin that is truly the world’s easiest landing page generator.

Magic Action Box: Magic action box is a fantastic plugin to use which you can instantly place a sign up form at the end of every blog post. It makes the job effortless. Another advantage is that it can be connected with your Aweber and MailChimp accounts thereby making it easy for you to gather new blog subscribers. This plugin can help you get more people to sign up for your blog updates. If you would like to, you can also use it as a popup form.

Optin Monster: Opt-In Monster is simply a way to increase the size of your  email list using a pop up email catcher!

Pippity: allows you to display a pop-up that isn’t too annoying for readers asking them to become a subscriber. It only pops when you think they have read the content they have come to read

PowerPress: posts your podcast content not only to your blog, but also pushes everything to iTunes .Makes the publication of a podcast so much easier for zero-tech-heads.

Q2W3: Q2W3 is a terrible name for a wonderful plugin. It’s job is to “stalk” your blog reader by making one (or more) of your sidebar widgets “float” as the visitor is scrolling up and down.(find these social floaters a complete turn off? So do I!!)

Scribe: Handy tool for evaluating keyword optimization of posts. Although, we focus on optimizing for people first and foremost.

Soliloquy: This is the best responsive WordPress slider. Simply great for image sliders on a page! It’s lightweight and easy to manage.

 Tweet Old Post:  Its job is simple. Take old posts and share them on Twitter at a configurable time interval

W3 Total Cache: We all know how critical load time is when it comes to increasing page views and subscribers. This free plugin has a ton of capability, but the most important is the caching of your site to compress your files and speed up the time visitors have to wait to view your latest post

WordPress backup to dropbox:  Just peace of mind > great to integrate tools you already use and love.

WordPress Editorial Calendar: Adds a visual editorial calendar to your blog seamlessly.

Yoast WordPress SEO: Makes it easy to manage numerous SEO and social settings for optimising your WP blog.