The following review written by one of the Software Informer contributors applies to version 2.0
ImTOO YouTube to MP3 Converter is a sound converter. The application can rip the audio off YouTube videos and convert it to MP3, MP2 or WAV or create an audio file without converting the source. YouTube has lots and lots of music videos and concerts on it, so this tool helps you to download those to your computer and play them wherever you want.
To start a download, you simply click on the "add" button and a new dialog will pop-up. From there, you have to tell the application the URL of the YouTube video and what format you want to convert the clip to. Alternatively, you can choose not to convert the song and leave it in an FLV file. There doesn't seem to be a limit of downloading tasks that you can have active. You can also download a song and then reconvert it at any time.
In my testing, I told the app the URL of the video I wanted to download, and I left all the settings untouched. ImTOO YouTube to MP3 Converter found the clip and started downloading. After less than a minute I had an MP3 file that sounded good enough. Bear in mind that YouTube isn't an ideal source for high-quality audio.
The trial version limits you to 3-minute files.