Here's how you can download the official Twitter app free for your iPad, iPhone, iPad mini or iPod Touch.
Download the Twitter App Free From iTunes
1. Go to the Twitter app preview page in iTunes.
2. Click the View in iTunes button.
3. Click the Free button to download the app.
4. Sync your iPad, iPhone, iPod Touch or iPad mini with iTunes to install the Twitter app.
Download the Twitter App Free From the iOS App Store
1. Open the App Store on your iPad, iPhone, iPod Touch or iPad mini.
2. Search for "Twitter" (without the quotes).
3. Tap the Free button to download the app and install it on your iOS device.
Here's a description and screenshot of Twitter for iOS devices:
"Wherever you are, Twitter brings you closer.
An organized stream of Tweets that delivers the best content to you.
All the media, news, events, and information you need.
Your world, expressed in Tweets and photos.
Search in real time. Follow people you’d like to know. Watch rising trends."