Tumblr is a great micro blogging service, where you can share all sorts of media, from text to quotes and audio and video. You can blog from your iPhone with this great official Tumblr app.
The official Tumblr experience
Pretty much everything you can do on the website you can do with this Tumblr app. The interface has five buttons at the bottom: Home, Search, Post, Account and Activity. Post is divided into the six types of Tumblr blog posts, Text, Photo, Quote, Link, Chat and Video. Each of these buttons in turn opens another interface where you can post the content you have chosen.
There are also advanced options so you can save posts for later, add to a queue and more. It's all really well integrated into the iPhone, so you can add pictures from your camera roll, or take new ones. The same is true for video, and with audio you can record directly into the microphone.
Follow and find new blogs
The Home will update with all the Tumblr bloggers you're following, just like on the website, and in Settings you'll enter your account details, and choose whether the app starts with the dashboard open or not. The app supports multiple accounts, which is partiucularly useful on Tumblr (perhaps more so than with Twitter).
Search shows you Trending Topics and recommended blogs, based on who you follow already. The activity tab shows you how people have interacted with yout Tumblr, whether comments, reblogs follows and so on.
If you use Tumblr, this iPhone app is a great way to do it wherever you are. It's user friendly, flexible and does everything you would expect it to.
The latest version of Tumblr adds new notifications, for Asks, Answers and Fan Mail. You can now also delete the app's cache if you want to save some space on your device.