Tools
General
ViewDNS.info - A list of a whole bunch of awesome DNS tools
Hurl.it - Make HTTP Requests
AutoPrefixer - Add the desired vendor prefixes and remove unnecessary in your CSS
Chrome Extensions
Check My Links - Scan one page for any broken links
Linkclump - Lets you open, copy or bookmark multiple links at the same time.
Accesibility
AXE Chrome Extension
Chrome Accesibility Tools
Image Compression
TinyPing - Run PNGs through this!
Background & Texture Generators
Transparent Textures - Lots of background textures. Just generate, download image and copy CSS
Site Origin - Another option. S’ok.
BGPatterns - More fun/colorful background patterns. Think christmas sweaters.
Favicon Generators
DynamicDrive - Ugly but gets the job done
iConvertIcons - Just another option.http://www.google.com/s2/favicons?domain=domainname - Favicon Stealer
Color Schemes
Coolors - Easy to use. Completely random color palettes.
ColorHunt - User created schemes
Backup
Sitesucker - Mac