A long time ago, in a galaxy far far away ...
Side-project where I wanted to send moeny to another entity/person using just their number. You share a contact with a whatsapp number (a bot actually), a link gets generated, and you hit pay (RazorPay). Never completed it, just putting it out there.
Shoved it becuase we now have UPI http://www.npci.org.in/home.aspx.
Stamping a GPL to ensure that any further forks/improvements are open sourced too. (Hit me up on @argvk if you want a more permissive license).