The animations available that are public and free fall under the Creative Commons licence 2.0
Be aware that from June 2020, animations on LottieFiles may have varying Creative Commons licence combinations, so always check which licence an animation you select is under.
You may use these in your web and app products. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
Here is an example of a product on the Google Play Store that has given credits to Lottie animations: