EndNote Basic is a free online program for managing references. You do not need to have EndNote installed on your desktop to register to use this program.
However it has limited features including:
EndNote App for the iPad
You can purchase the EN app to use on your iPad through the iTunes app store
EN iPad will sync with your EN Online library and the desktop EN library
N.B. Cite While You Write in Word is not available with the iPad app
EndNote Basic is a free EN online based program - you do not need to have the EN program installed on your computer to use this.
This video is a good introduction to using EN Online including how to download the installers for Firefox and Internet Explorer for direct export from databases, sharing groups, using CWYW, and attaching files.