I want my android app to get the users eth address from the Metamask mobile (MMM) app. AKAIK it is the only way to get it. I have a simple 1 page dapp on my web site that makes sure the user is connected to an account and gets their eth address. My app open this dapp via the MMM apps deeplinking ability. I can choose the account but then i hit a wall. I have a deeplink back to my original app that passes ther address back and works when i run it from chrome but it doesn’t work in MMM. It just opens the link as if it was a web page and does not launch my app.
I am guessing the OpenSea app does something similar as their app goes to into MMM and back again to log in.
The deeplink back looks like this (minus the spaces) and does work on the phone from chrome.
http : //nftgallery/address/0x1234567890