Sep 4, 2010 10:13 GMT  ·  By

Twitter seemed to stall for a time, after some months of huge growth. But the site is now back in the game and is seeing some impressive growth, especially from mobile apps.

Twitter CEO Evan Williams published a rather informative post on the Twitter blog, revealing some interesting numbers in terms of usage.

First, the service keeps on getting bigger, there are now over 145 million monthly users, up significantly from the 100 million Twitter touted earlier in the year.

And there are 300,000 registered apps using the platform through OAuth. Note that these may not necessarily be unique apps since one app may be registered several times.

What's more, ever since Twitter started offering its own 'official' apps, mobile usage has skyrocketed, growing by over 62 percent in that time.

"We did iPhone user tests and confirmed that even though there was a plethora of third-party Twitter apps, people were having trouble finding and selecting one because none were called 'Twitter.' This kept them from using Twitter at all," CEO Evan Williams says.

"For this reason, we acquired Tweetie and turned it into Twitter for iPhone... We quickly understood that we were doing users a disservice by not having a great client on each of the major mobile platforms," he adds.

This proved to be very successful. Not only total usage was significantly up, user registration from mobile apps is now at 16 percent. Before the official mobile clients, the figure was at five percent.

Yet, the most remarkable thing out all of this is just how little the mobile apps are actually used. Twitter provided a chart that showed the top ways users connected to the service.

Twitter.com comes at top, as expected, but what's interesting to notice is the disparity between the site and the rest of the apps. 78 percent of Twitter users logged in though the site.

14 percent used the mobile version of the and another eight percent through SMS. The official iPhone app accounted for 8 percent and the Blackberry app for 7 percent.

On the face of it, it would look like the site is, by far, the preferred way to use Twitter. But it's not that straightforward. Twitter counts just unique visitors, however, a single user may be counted twice.

If a user visits Twitter.com once in a month and uses the iPhone app 100 times, both would be counted the same. And, since most people end up using the site at least once during a month, even if its clearly not their preferred way of using Twitter, Twitter.com gets 78 percent.

Still, what is clear is that the official Twitter apps are by far the most used, so the strategy is paying off for the service.