Tinygrab allows you to grab screenshots and parts of your screen to share on social channels - great for photo-sharing sites and sharing images on Facebook/Twitpic
URL shortener, for use in Twitter and other social posts and updates, which allows click tracking - how many people clicked your links? Bit.ly shows you what posts have caused the best reaction and engagement.
Buffer takes your tweets, and sends them at the optimal time - the time at which your followers have shown themselves most likely to see, share and clickthrough on links.
Kred - Measures influence based on the propensity of others to share your content and mention you, as well as your outgoing engagement (Mentions and RT's for Twitter, for example)
Sell & promote digital products, including audio, video and whitepapers/ebooks - integrates with Paypal, and allows you to discount your products if the buyer shares it via their networks
Turn your photo's and vdeo clips into a professional-looking, edited video, with rights-free music. Free option, and professional HD options as an upgrade.