Opal - Ambient Sound is described as 'Select the sounds (30+ relaxing tracks are available) that you want to hear, turn them on and you can listen to and enjoy the music for as long as you want, without interruption. You can listen to the sound of:' and is an app in the sport & health category. There are more than 50 alternatives to Opal - Ambient Sound for a variety of platforms, including Web-based, iPhone, Android, iPad and Mac apps. The best Opal - Ambient Sound alternative is Ambie, which is both free and Open Source. Other great apps like Opal - Ambient Sound are Moodist Ambient Sounds, Ambi, Noice and Blanket.