I loved every second of using it. So much cheaper and you can call and text from everywhere in the world as long as you have an internet connection. Being able to make calls on the desktop with a desktop xmpp client is great also. if you need help, they have a very reactive support and they also gave a chat room where the employees are very active. I used for about two years and then I stopped because some services require a physical SIM card phone number (they reject VoIP ones), and I could finally find a cheap enough plan to justify not using JMP anymore.
It's exclusively my phone number using Cheogram app from F-Droid. I paid for 2 numbers, one number is for bank and credit cards, I use that number to call financial places or verify login. My other number is my personal number and for Molly/Signal, etc.
Since JMP only requires XMPP, a federated service, it's essentially an anonymous phone service, and if you travel internationally, you connect to wi-fi in a different country and can make local calls to anyone back home.
All it is is a VoIP number, and some services detect a VoIP number and require a cell number, but you can port your cell number to JMP, you don't have to have a new number from JMP.
IIRC it's legally required to allow porting a number out of a service, but porting it in is usually something companies add as a nicety. It's good to hear they allow that.
Two questions, which are open ended:
Does porting a number out to them cause the number to get flagged as VOIP later? It would be really crappy for people if it did...
I use Linux so my client of choice is Dino. If you are on Windows, I think there is Gajim that is recommended by JMP, and it is cross-platform, not windows or linux exclusive like Dino. This should also be of help: https://wiki.soprani.ca/ClientComparison
First time hearing of this, does it work from outside the US? Not like, buy it in the US, use it anywhere, but, buy outside the US, use outside the US. How does it work with countries that need registration to own a phone number?
it's been great for the most part. i think if you got a regular tracfone or tmobile number and then ported it to jmp, it would be the ultimate solution for a non-tracking (cellular tracking) phone number while also not being blocked by various services for using a "voip number"