A free app for Android, by HappyMusicTime.

Audio Editor is the best in class Music Editor. It’s an easy-to-use music MP3 Cut-and-Mix Tool that allows you to easily Mix Songs and play music and create Cool Ringtones.

Audio Editor is an easy-to-use mp3 cutter, mixer, and music converter. You can add clips from your phone or SD card and mix them together with great quality. It’s an mp3 cutter that can help you create ringtones or play music to suit your needs.

Mp3 editor is a useful audio cutter. You can play your music and listen to your favorite songs in just one app. It supports all popular formats: mp3, wav, wma, flac, aac, m4a, etc. 

A powerful audio mixer. You can mix several songs with good quality and create awesome ringtones. It supports various types of music including rock, pop, R&B, blues, jazz, and many others.

You can record your voice and use the built-in audio recorder to record music clips from your phone.