You start and stop a recording by simply tapping on the screen. As you record, there's a beautiful level meter / recording visualisation consisting of flashing background squares, in the same style as Nokia's Lumia marketing campaign videos. The app keeps working under the lock screen, which means the recording of voice notes longer than a few minutes should pose no problems.
Recorded items are shown in a simple list, sorted by date. Tapping on an item open up a details page, from where you can play back the audio, edit the name of the recording, add text notes and attach a related photo.
An upload button on the bottom toolbar gives the option to upload the audio to SkyDrive or Dropbox. Audio is stored as .wav file, text notes as .txt file and photos as a .jpg file. In the case of SkyDrive the notes are uploaded to a folder called MetroRecorder, in the root of your SkyDrive.
Mini Recorder Free isn't a feature rich or complex application, but it stands out thanks to the elegance of its minimalist design and user experience. If you're looking for a simple dictaphone style app you'll be hard pushed to find anything better. The app can be downloaded from the Windows Phone Marketplace for free.