Search Twitter using a large variety of filters. The resulting searches can be saved, as well as adjusted within the search box or the url
A custom search that allows you to use Google to search for Twitter lists by keyword
A tool that allows you to copy entire Twitter lists to build your own. Created by Noah Liebman. Also available on Github if you feel like tweaking it to suit your purposes
Allows you to quickly search for Twitter lists based on keywords
Tracks changes to Twitter account profiles
Gives statistics on Twitter accounts - tweet times, most-replied etc. From Luca Hammer
User-friendly interface giving account analysis, including for interactions between accounts
Account analysis tool. Attractive, easy-to-use interface and the option to export the analysis as a pdf file
Account analysis tool. Detailed and with an easy-to-follow interface. From Japan - in a couple of places the English is slightly unclear
Account analysis tool. * Does not require you to log into Twitter
Account analysis tool. Very useful for exploring Twitter bios to find accounts of interest
Account analysis. Also follows general Twitter trends. Offers more comprehensive service for paid subscription.
Account analysis that allows multi-language searches and saved snapshots of results. From NU Knight Lab