This is not correct. First off, you do not sign any events so your npub can't be associated to anything (and when it happens it will be totally transparent and voluntary). Elsat is also right that you can log in with any other npub. Also, we do not check IPs or perform tracking.

Lastly keep in mind this is nostr, you can create a new keypair at any time. 

 Thank you! I think I understand better now. I didn't think about the obvious amount point you made. Also, I overlooked that what's being checked is the signer's identity. I thought it would show me whether a friend has Fountain installed or not. Thank you, and Elsat, for your patience.

FWIW, I have enjoyed zap.store for the short time I've been using it 

 All good, thank you for asking! And for using the app 

 At some point friends will be able to share if they're using Fountain but again - that will be transparent and voluntary 

 You are right to point out these questions! If you have them, others certainly do.

Taking 📝