F7Social

Add Live Chat capability to your website, so visitors can immediately engage with you, while they're still on your site! More engaging than contact pages/forms

Roboform password management - this plugin for Chrome allows you to store your passwords in one location, allowing login to all your services from anywhere.

Basecamp from 37signals allows collaborative project management, to-do lists, messaging, etc.

Social Project Management, including a mobile app for collaborative working

Trello allows collaborative project planning - showing you who's working on what, at what time

Teamwork is a Project Management tool, allowing online collaboration on projects

Make your website social - allow visitors to share from within your site, aiding link-building and SEO, as well as social discoverability.

See users social profiles and more about them, from within Gmail - displays alongside incoming email

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.

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

Schedule emails to go out when they're likely to make the best impression - integrates with GMail

Mailchimp is an email newsletter and email marketing tool - free up to 2,000 list subscribers - and allows autoresponders to be set up.  It also offers great analytics on views, clickthroughs, etc. and integrates with Highrise CRM and a variety of other tools.  Great email template designs, too.

Adroll is a retargeting platform - which helps to re-capture visitors that leave your site, via targeted ads on sites that visitors use AFTER they have left your site.

Thank your customers/clients/partners, by buying them a beer ... from anywhere in the World!  A quirky way of saying thanks

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

Inboxq find questions being asked in social media (Twitter) by recognising questions around the keywords you provide.  You can also refer a question to your trusted contacts, for them to answer, and create new, targeted connections as a result

Twitter productivity tool - allows scheduling of messages, and a variety of other tools to help you "be" in Twitter without actually being there!  Apply caution - People like true engagement! (Well durrr)

Yellow Pages for Twitter - A directory listing of Twitter users based on their known areas and topics of specialism

Clean up your Twitter account, by finding those who rarely tweet, who have no profile picture, who don't engage or respond, who over-promote themselves - allows for better relationships and likelihood of engaging new business/relationships