There are so many Twitter apps, and many new Twitter apps are coming daily, they can be a simple web app which you can use in a browser, you can download for your computer or mobile. Or you can just use it on website. How to know when new application is lunched? If you do not know about resources, perhaps you will never know, but today I am going to share some of Twitter apps directories, so any time you can visit and know about all that apps.
Some of directories are famous and large and some are small and not so popular.

All Twitter apps are not for free, some of apps you have to purchase.

Oneforty

Oneforty is most famous Twitter app and tools directory.

Twitdom

Twitdom is another famous Twitter apps directory.

Go2web20

Go2web20 is web 2.0 apps directory, so I have taken only Twitter apps category link.

Pbworks

This is a Twitter fan wiki, you also can edit it.

Twitterappsdirectory

Bustatweet

Twtbase

Tw1tter

Twi5

This is for Twitter applications and tools.

Twit-apps

Twapps

This is also for Twitter apps.

Justtweetit
This is a user directory but an apps directory also.

Twitterpassion
This is a user directory but an apps directory also.