Coming late to the iPhone I am just starting to explore what Twitter Apps work best for it.
I started out by downloading my beloved Tweedeck for the iPhone. We did not get on. It's not intuitive to use, in fact I am not sure if I did use it at all for three weeks although I tried too.
Columns wouldn't update and generally a clunky feel that I didnt feel comfortable with.
This saddened me as I love Tweetdeck and it's my app of choice for my PC.
Next I tried the Hootsuite App, and although better than Tweetdeck it really wasn't quite right and neither was Tweetie which my fellow twitter friends raved about. I groused a bit on twitter about it and Hootsuite were very supportive and gave me lots of help and advice.
In the end I gave up, user compatibility issues, in other words I didn't get on with it.
As for tweetie, it was just yuck (sorry tweetie fans)
I am starting to sound like Goldilocks here, too clunky, not clunky enough… and for a while, it seemed like there was nothing out there for me 
(although may say this was a blessing in disguise 
) A quick reminder, I am not a techie or geeky person and what may seem natural to some, can completely bamboozle me! Why do they never design these apps for use by ordinary people like me!
I then tweeted out and asked what other people used and it was Mark Lee (@bookmarklee) who suggested Echofon.
There are two versions, the free version with advertising in and the 'Pro' version which comes without advertising and will push notifications from all users rather than just Echofon users as per the free version.
It was love at first tweet 
Reading up on Echofon I found they created another App that I liked, Twitterfox again it was easy to use and fairly intuitive, so I downloaded it and tried it – did I mention it was love at first tweet?
For me the simplicity stole my heart, it's so easy to add a pic to your tweet. No longer do I download them to the PC and upload them to the Twitpic website, I can send them direct from the iPhone through to Echofon and twitter.
The tweets are easy to read, it has lists and it does all the things that I need it to do, it is made by Naan studios, and I love it to bits. So if you are fed up with Tweetdeck, lost in Hootsuite give Echofon a go, I am glad I did.
A guestblog from @essex_courier – Sarah Arrow
PS What do you use, and why?
I personally don't have an iphone – still waiting for my new BB to arrive arrrgghhh. But I have used Echofon for a couple of years now (the plugin for Firefox) and find it really handy – especially on my netbook when I'm on the go. That's the great thing about apps there's one out there for everyone!
Try the Birdfeed 1.2. It has a clean simple and clean user interface which you can easily understand. It's menu provides quick access to the user’s timeline, mentions, direct messages, and favorites as well as options to view their own profile, tweets, or perform a search. There are lots of iphone applications that you can use for broadcasting your tweet. Did I mention I'm a tweet fan too?