Portable animated interactive postcard for Android and PC

Simple animation with interactive triggers, like a button to press to continue or replay, would be included in a file that I could send to my contacts via email, messaging services, or social media.
Video Production Services once used Flash, but I have no idea how to do it now that it has been retired. It should ideally be in a vector format to reduce file size and be platform-independent so that no special software or app is required to view it. Any thoughts?