A free app for Android, by The AppGuru.

This app allows you to easily convert your M4A files to MP3 format. It supports all popular audio formats, so you can easily convert your M4A files to MP3, AAC, AMR, FLAC, OGG, WAV, and others.

Conversion Process:

First of all, you need to install the app. You will be guided through the installation process.

Next, you need to select your audio file. You can select either M4A or MP3.

Now, you need to select the output format you want to convert to. There are many options to choose from.

You can also set the bit rate, sampling rate, and channels.