These are earned numerous ways, depending on the individual app and whether or not you're playing on iPhone, Android, or Amazon. Purchasing rewards requires myVIP points (called loyalty points in the past and still called that by many). Always give the apps permission to use your location, because many rewards won't show up without it.
Log in to these apps with your Facebook account or Apple ID so they'll be tied to your name and e-mail (you need to show ID when redeeming rewards in Vegas and the name has to match your account). Tetris (currently many players are having issues getting this app linked with MyVegas, I gave up on it)
There are 7 apps in the MyVegas system, along with the Facebook game on their desktop website.
