What app do u recommend?

You don't have to reveal your number... You can use any number or other services. Number is only a username because you need an SMS in order to get the code but is not the number you really use to call or text. E.g. I use a different number from my "official" one to register Signal and the sim related to this number is in my drawer :-) Read this: https://source.opennews.org/articles/shields-using-signal-without-your-phone-number/