Marketplace
Moved to Forum: Original Link
REQUIREMENTS:
•iPhone must have iOS 6.1 or higher
•A free Microsoft account is required to use OneNote for iPhone (Available at signup.live.com)
•To connect your notes to SkyDrive Pro, sign in with your organization's Office 365 or SharePoint account
•OneNote for iPhone opens existing notebooks created in Microsoft OneNote 2010 format or later
Now available for free for a limited time
Windows Phone use here. I was a big fan of evernote until I used OneNote. Simple clean interface and I love it. Syncs with the windows 8 app. Highly Recommended.