Backpack began to e-mail invite codes to all those that registered for the http://backpack.app/download waitlist.
Check you email if you got the code.
You can install dApps from xNFT library with Backpack.
As many users may already know, the dApps inside Backapck are safe and very low possibility of scams.
It is possible to control dApps inside Backpack wallet by yourself securely.
xNFT Library
Source: Backpack