Today, nostr:npub1t3ggcd843pnwcu6p4tcsesd02t5jx2aelpvusypu5hk0925nhauqjjl5g4 suggested an interesting idea to me: Offline Reusable Custom Lightning Invoices as simple QR code.

You can store the on your Apple Watch, and anyone can send you money with any amount by simply scaning it.

It will come with Split payment feature. Here is an example.
https://i.nostrimg.com/db27114196e629c25e109bd77ba2198d7a5e50ddb3880b82ae2340ba54abfe3b/file.jpg