it's the most easy mobile app to pay and receive bicoin on the Go. It connects to your Alby Hub. - The sats are on the Hub but you use the mobile app to send/receive on the Go.  

 so it only connects to my Alby Wallet - no other wallet? 

 It's the mobile interface for your Alby Hub. 
it uses the NWC protocol so it also works with other wallets that use NWC.  

 Thank You!!! 
Another stupid question - sorry.
How can I find out if another wallet uses the NWC protocol?