Twitter’s open API has enabled the development of thousands of tools – some of which are quite handy. Jason Hiner singles out some of the best ones.

One of the biggest reasons for Twitter’s growth and success is that the Twitter team allowed the service to be morphed and reshaped by the user-base from the very beginning. We saw it happen in the way that the Twitter community instituted replies, retweets, and #hashtags.

But the real kicker was the fact that Twitter released an open API for developers. That allowed programmers to extend Twitter in lots of directions and experiment with tools and utilities to improve Twitter.

In 2007, Twitter co-founder Biz Stone told ReadWriteWeb, “The API has been arguably the most important, or maybe even inarguably, the most important thing we’ve done with Twitter. It has allowed us, first of all, to keep the service very simple and create a simple API so that developers can build on top of our infrastructure and come up with ideas that are way better than our ideas.”

Today, more than three years after Twitter originally launched, thousands of tools have been developed from the API, and many of them are extremely useful. Below is my list of the 10 most useful Twitter tools for business users.

Note: This article is based on an entry in our Tech Sanity Check blog. It’s also available as part of the PDF download A quick Twitter guide for business users, which explains 10 key Twitter concepts and lists 100 tech experts worth following. You can also follow Jason Hiner on Twitter at: @JasonHiner.

1: Bit.ly

This URL shortener not only shrinks links down to about 20 characters, it also keeps track of your links for you and provides some basic analytics to see how many people click and retweet the links and where those users are coming from.

2: Twitpic

The most popular tool for sharing photos on Twitter is Twitpic, which allows you to take a photo on your mobile phone and email it to a customized Twitpic email address. You simply type your tweet into the subject line of the email. (See also: Flickr2Twitter.)

3: Tweetscan

If you’ve ever used Google Alerts, you’ll understand Tweetscan. It scans Twitter for your keywords and sends you a daily or weekly email of all instances where your keywords were used. This can be especially helpful for tracking brands. However, the service is not free. It costs $20/year.

4: Twitterfeed

Twitter is great for promoting blog posts and other types of content. If you have a blog and you want to automatically send out a tweet every time there’s a new post, Twitterfeed can do it for you. It also has some nice customization options.

5: TwInbox

If you live in Microsoft Outlook — like many business professionals — and would prefer to interact with Twitter from there, TwInbox integrates Twitter into Outlook. And the product is free. It was formerly known as OutTwit.

6: CoTweet

CoTweet provides an entire business workflow for companies that are serious about using Twitter for business. CoTweet allows you to manage multiple Twitter accounts and enables multiple users to access a single account. It can also assign tweets to employees for follow-up, monitor keywords and trends, track clicks to links, and allow employees to schedule future tweets. This is not a free tool. (See also: HootSuite.)

7: TweetStats

This site provides statistics for individual Twitter users. Simply plug in the person’s Twitter username and you’ll get a plethora of stats, such how often a person tweets, when the person tweets the most, who the person replies to most often, who the person retweets the most and which interface the person used the most to post on Twitter. (See also: TwitterGrader.)

8: Twuffer

This free tool allows you to schedule future tweets. For example, I like to post an inspirational quote of the day on Twitter. But sometimes when I’m looking up quotes, I’ll come across several good ones at a time. So I use Twuffer to spread them out over several days.

9: Twtpoll

One of the most useful things to do on Twitter is to crowd-source a question or post a quick straw poll. Twtpoll makes it easy to officially do a poll. (See also: StrawPoll.)

10: Twendz

If you want to see how a keyword has been viewed over time, Twendz provides a simple and useful chart. The chart is updated in real time. (See also: Twazzup, Twist, and Twittercounter.)

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