AMR is an audio file that was made with Adaptive Multi-Rate ACELP Codec.
If you have one or more .amr files and you want to convert them to a more popular format like MP3 or WAV, follow these steps.
Download and install AMR Player from this page (is free).
Open the application and add your .amr file(s).
Click AMR to MP3 button if you want to convert it to MP3 file.
Click AMR to WAV button if you want to convert it to WAV file.
Choose a name for your final file and click Save.
The conversion will begin and in seconds your file will be ready.
Is very simple and is completely free. This tool also supports the reverse format conversion (from MP3, WAV to AMR).