I use this almost every day. I guess i need to make my own.
They use twilio for google voice/sms. I paid 9.95 like ten years ago to set up the account with a fixed number and be able to call/receive calls. I've been using it for 10 years and I don't think they have touched my account balance.
When they shut it down I'll ask for a refund lol. And maybe demand they port my number. :)