There are a heap of good tutorials online. Have a go at making the things you want? The reason that you have to use the system lock screen is because google decided to not let you use the user credential store unless you have a google lock screen enabled. You could try use the Smart Lock feature. I.e. set a google lock screen then enable the google "Trust Agent" and enrol your NFC tag (i think it was added in lollipop or marshmallow). That'll let you use your nfc ring with the google lock screen but there are a group of users that have found this to be unreliable (myself included). There are open software bugs with google but until someone explains the exact cause to google, they're not likely to fix it. What "multiple things" do you want? the ring basically has an ID and a section to store data (888 bytes or something).