Who are you following that’s not following you back? Who’s following you that you’re not following back?
Friendorfollow will answer this question for you giving you the choice to order the results by Username, Name, Location, Followers, People they are following, last tweet or account age.
It’s a useful service to discover who is not following [...]

Twittercounter allows you to check your stats of followers you gain, or loose if you become an spammy user, everyday. It’s a real addicion. Remember this words:
there are only two kinds of Twitter users: those that want more followers and those that are lying

http://www.khaces.com/asyrix

Twidroid is the industry-standard twitter client for android and among the most used twitter applications across all platforms.
It’s available as a free and commercial pro version that supports all twitter features as well as functionality that is customized to the capabilities of android devices.
Link | Download Twidroid

Twitterfeed is just the way to feed your blog or RSS sources to your Twitter account. You just have to follow 3 very simple steps:

Create your account, or login using OpenID.
Add your feeds from your blogs, tumbler, khaces or whatever.
Enjoy updating your twitter account and tracking your stats.

Enjoy feeding!

Here there is my top 10 twitter applications. I hope they are useful to optimize the time you expend on Twitter.

Twitterfeed: Update via RSS.
Twitdroid : Android application.
Twittercounter: Stats for your profile and featured users.
Friendorfollow: Check who is not following you back.
TweetDeck: Twitter Desktop application. Best ever folks!
Twitxr: Send pics to your Twitter profile via mobile [...]