Login with lightning. No email needed.
nostr:npub18tcc00lqpysdsurg567dllzg7jeyr5wcyk2v6w23rx3s3ygyze2qv32nxx your app needs a way to manually verify an email. Graphene won't open the confimation email link in the app even with your app open. Link just goes to play store in the browser.
Discussion
Auth47 Paynym logins work well for this too!
Although the best workaround for an email/password account is to just sign up via the web app (https://app.thebitcoincompany.com/signup), then use the details to login to the mobile or web app from there.