No, the APP is the “burner phone”. It’s like the internet phones you can buy for home that plug into your PC or network, except this is an app on your phone, that gets a phone number and can receive texts /calls for 3-4 bucks a month. You don’t have to drive anywhere.
I’ve not used it, but the concept is sound, and ought to work…
I know the concept you’re talking about. I use TextFree, because you can use it from your PC (http://textfree.us), although you need to sign up on a device. I used my tablet on WIFI to sign up and get my free number. There is no charge ever, although they want to entice you to pay a small amount to “keep” your number. But the only way to “lose” your number is through a month of inactivity, and since I text people often, that’s not a problem.
I do not believe a TextFree number would work for Telegram, though, because Telegram requires inclusion of the ‘1’ before the area code, and TextFree just uses a 10 digit number, and you enter 10 digit numbers to text people - it does not require, nor even recognize, the ‘1’.
There might be other apps like that which would work for a Telegram signup. You just have to find one that uses the 11-digit phone numbers.