It's not limited to Chase. It's called clearXchange and was started by the 3 big banks (Chase, BoA, Wells Fargo) and is now extending to more: https://www.clearxchange.com/payments/member-banks

clearXchange allows account holders in any of the member banks to send funds to each other and it takes about 1-2 days after the first transaction. It also allows sending funds via cellphone. If you have a Wells Fargo account, you can send funds to a BoA account holder using just their phone number.

I think the banks have done a horrible job of advertising this free no-strings-attached service.

Canada has a similar solution, but it works across all of the big banks. Chase's solution is only for Chase customers, though it appears that the recipient doesn't necessarily need to be a Chase customer.

https://www.interac.ca/en/interac-etransfer/etransfer-detail