Really neat!

Any plans on open sourcing the formatting library?

It's a good functionality, but (at least for me) would mainly be useful for view-layer on-the-fly formatting, and we wouldn't use an remote API request for that.

Sort of like Strip's jQuery.payment[1], it would be a simple and clever marketing trick. People searching for a phone number formatting library are just the people you want to sell your services to.

EDIT: just found libphonenumber, which does local formatting[2]

[1] https://github.com/stripe/jquery.payment [2] https://github.com/googlei18n/libphonenumber