Felix is an iPhone client for the Twitter-like social network called App.net. There may not be very many iPhone apps available for the service, yet, but even with little competition, the folks at tigerbears have done a beautifully phenomenal job with Felix.
Felix features five main tabs: My Stream, Mentions, new post, Global, and Dashboard. Each post that appears in My Stream and Mentions displays the user's avatar, username, and buttons to reply, repost, and mark as favorite. The default for the reply button is to reply to everyone mentioned in the post, but if you want to only reply to the poster, tap and hold the reply button to get the option to "reply" or "reply all". Similarly, tapping the recycle icon will repost with the method you've chosen in the app's settings, but tapping and holding will give the choice to "repost" or "repost with comment". My favorite gesture on the My Stream and Mentions tabs is that swiping to the left on a post will open up its conversation. If you want to save the conversation for later reference, just tap the star at the top of the page.
The middle tab that looks like a signal is where you go to post to App.net. As soon as you tap it, the post creation screen will slide in. It super fast and easy. The Global tab will show posts by all App.net users.
Your Dashboard is where you go to access your profile and settings. The animations on the Dashboard (and profile pages) are really fun. At the top of the screen you'll see your cover image, profile picture, and name, but as you scroll down, these three elements collapse into one bar with a smaller version of your profile pic and your name displayed over a very skinny section of your cover image.
In Settings, you can enable push notifications, change the default repost style, login to the droplr, CloudApp, Pocket, Instapaper, and Readability, and more.
Felix is a beautiful App.net client for the iPhone. It's fully-featured with a gorgeous UI, intuitive gestures, support for other media and read-later services, and push notifications that have a very nice sound. I have downloaded a few different App.net clients on the iPhone, but I keep coming back to Felix.