BuiltWith - Find out the technology behind websites
Clientflow - Project Management & Shared Inbox for Client Service teams
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Client Portal - A client-friendly way to keep your projects organised
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.
Task Pigeon - Create, assign & manage your teams everyday tasks