AIM is AOL's instant messaging platform. AIM offers a free iPhone application through Apple's App Store that you can use to send and receive your AIM instant messages on your application. Once you download and install the AIM application on your iPhone, you can go on AIM by opening the AIM application and logging into your AIM account.
Tap the "APP Store" icon on your iPhone.
Select "Search" and enter "AIM" in the search bar.
Select the "AIM" application.
Tap the "Free" button and tap the "Install" option.
Tap the new "AIM" icon on the home screen of your iPhone.
Tap the "AIM or AOL" button.
Enter your AIM username and password and tap the "Enter" button on your iPhone's virtual keyboard to access your AIM account.