Sites for Free Sound Clips
These sites are sites that have give you access to hundreds of free sound clips that you can download and apply to your games animation or app development. Most of those sounds requires that you credit the creators on your projects. Other than that these assets are free to use on your animation and game developments.
CloudBibble is a go to Site for Game development. You want punching sounds, nature sounds, walking sounds, gunshot sounds for your game, Cloud bible will help bring your game, animations and apps to life.