Audio Memos is an iOS app for creating and sharing audio messages. The app is available in three versions. The free version is limited to 3MB recordings, the $0.99 version is limited to 15MB recordings, and the "pro" $9.99 version has a nice selection of audio editing tools built-in. Some of the features that are available in all three versions of the app are automatic pause if a call comes in while you're recording, recording volume controls, and recording even when your iPhone or iPad goes to sleep.
Here is a video tutorial on Audio Memos.
Applications for Education
I learned about Audio Memos from Silvia Tolisano's recent post about using voice recordings and QR codes in a lesson that integrates Art and Language Arts. I encourage you to read Silvia's post.
In addition to the ways in which Silvia described using Audio Memos, the app could be great for journalism students to record interviews and then play back the recordings while creating the written version of the their interviews.