Loren Brichter is a legend amongst iOS developers. The 28 year old developer is the creator of Tweetie, which eventually became the official Twitter app. He’s the guy behind fan favorite word game Letterpress. He’s the creator of ‘Pull To Refresh’, cell swipe and slide-out panels that have become synonymous features in mobile app development. Yet few people who aren’t app and design junkies even know who he is.

You may not know Loren Brichter by name, but you know what he has made. After leaving Apple, Brichter originally became famous for Tweetie, an innovative Twitter client for the iPhone. Tweetie was such a success on both iOS and OS X that Twitter ended up hiring Brichter and making Tweetie its own official app. After leading the development for Twitter for iPhone, iPad and Mac, Brichter left Twitter last year. He’s been keeping himself out of the spotlight, but now it looks like he’s coming back into the iOS scene with a new game.

Brichter’s company, atebits, hit the 2.0 stage today. Expect the new game to go live in the App Store any moment now.

Kicking off this week’s must-have apps roundup is an awesome new Twitter client that reminds me of the old (and awesome) Tweetie app — before Twitter bought it and ruined it. It’s accompanied by Camera+, which now supports the iPhone 5’s larger display, and comes to the iPad; an awesome new update to Mixel; and more.

Last March, Twitter told the developer community to stop making third-party apps and clients that “mimic or reproduce the mainstream Twitter consumer client experience.” Twitter said, “We need to move to a less fragmented world, where every user can experience Twitter in a consistent way.”

Fast forward more than a year later, and Twitter is slowly moving away from an open platform for developers to build upon. Twitter plans to implement stricter API guidelines for developers, and while there’s no concrete evidence that Twitter will shut down third-party apps altogether, the current landscape of great apps like Tweetbot and Twitterrific could look very different in coming months.

Loren Brichter, the developer behind Tweetie and its hugely popular pull-to-refresh gesture, which has now made its way into countless iOS apps, has spoken out about Twitter’s recent move to patent the feature. Speaking on the One More Thing podcast, Brichter said that there’s really no need for people to worry about it.

Fluent is a web-based wrapper for your Gmail account that clearly takes cues from the much-loved (and sorely missed, by some) Tweetie Twitter client and the much-loved (and still very much alive) Sparrow mail app.

Osfoora, a popular Twitter client that made its debut on the iPhone, has made the leap from iOS to the Mac. It is now contending with the likes of Echofon, Twitterific, and Twitter in the Mac App Store, but is it worth its $4.99 price tag?

With the introduction of the App Store’s new ‘Purchased’ feature at WWDC yesterday, users can now download old iOS applications that may no longer be available for purchase, such as the original Tweetie application that is now Twitter.

The first thing you’ll notice about Twitter v2.0 for the Mac, which is available for free via the Mac App Store, is that it doesn’t look like a regular Mac OS X application. The applications author, Loren Brichter, has completely tossed Apple’s Human Interface Guidelines for the Mac aside and Apple not only allowed him to do so, but allowed his application into the Mac App Store — much to the surprise of many developers.

I’m surprised that Apple, which has been so overly anal about iOS apps in the iTunes App Store, would allow this in the first place. I don’t know about you, but I’m beginning to wonder about Apple and the future there. It’s probably the forgone merger of the iOS and Mac OS X GUI interfaces. I’m not sure I’m ready for that – I’ve always boasted about the Mac OS X interface and how it improves my work flow.

So outside of the controversy about Twitters unique GUI it isn’t all that bad if you are looking for something simple. Some of it is actually kind of neat, yet that doesn’t overshadow the fact that it falls short of the iPad version that it appears it is trying to emulate.

A few months ago, it seemed like I switched OS X Twitter clients every other day. A long time Tweetie user, the lack of updates eventually made me ready to switch, but after plowing through client after client in rapid succession — Twitterrific, TweetDeck, twhirl, YoruFukurou — only to keep turning back to Tweetie for the admittedly nebulous reason that none of the competition felt “right” to me.

That all changed when I discovered Kiwi, my new go-to Twitter client. Despite the fact that a change to Twitter’s API meant that Kiwi often alerted me for @replies that hadn’t actually shot down the pipeline, I finally deleted Tweetie from my machine and became a Kiwi user full time.

I’m delighted to see, then, that Kiwi has been updated to its second major release, Kiwi 2. It fixes the aforementioned @reply bug, but also adds a host of new features like account grouping, inline images, gesture support for multitouch trackpads and the extension of its already-excellent themeable interface.

If you’ve been looking to trade in Tweetie for a client with more advanced features while retaining Tweetie’s simplicity and streamlined presentation, I’d recommend Kiwi 2 heartily. The ad supported version will cost you nothing, and removing the ads is a one-time fee of $9.95. Worth twice that, if you ask me.