Adding Sound to Your Animations
On iOS, you can use iMovie by Apple to add sound to your animation.
From Animatic app, Export your animation as Video and save it to Photo Library. Open iMovie, create new project of Movie type, import animation from Photo Library and import Audio from Theme Music, Select Done and you are good to go!
Alternatively you can use Splice by GoPro. Which we have found to be very lightweight and with a great selection of sound tracks.
On Android you can use one of the many video editing apps available on Google Play.