Shrey Gupta

I am currently using the before mentioned extensions and am truly loving the same. 

Requestly (Extension to Intercept & Modify HTTP Requests)
Web developer checklist (Extension to analyze any web page for violations of best practices)
Wappalyzer (Identify underlying technologies behind web pages)
Check My Links (Link checker extension)

I have been using these extensions for a long time now and they are my all time favorites. Any suggestions except for these would be appreciated.

I am a developer and want to know about some best extensions that could help me in increasing my productivity as a developer.