TLDR: We can hang money on words (and tips.bitcoin.com has done the hard part: non-custodial, auto return of funds after X days, clean simple design). Hanging money on words (strings) is itself too much possiblity for one brainstorming session.
Consider the situation where you don't get the opportunity to explain bitcoin to the person you're tipping, such as leaving a tip for the hotel maid.
I want to be able to write this down on a scrap of paper and leave it:
Thank you! I left you $5 at chequepad.cash/ilikeyourshoes69. Please grab it in the next few days ;)
This almost exists at tips.Bitcoin.com, but the password portion of the URL is assigned by the service and it's unwieldy for pencil & paper (twelve case-sense alphanumerix is a pain point whether you're reciting it, typing it, or writing it).
I would like for there to be an alternate version of this excellent tip application that lets me choose the unique/password portion of the URL. (I take responsibility for obscurity and uniqueness.) The other benefit is that I can write the cheque quickly even before funding it. I can load it later, in the taxi. This also makes it easy to pass Bitcoin in a common voice phonecall by just saying the URL.