I cannot really understand the use of this vexl app, but if it is about:

> At the Vexl Foundation, we sponsor projects that promote and enable personal and financial freedoms and self-determination. Bitcoin is the ultimate tool of this mission and we spent countless resources trying to give back and preserve its very nature: a peer-to-peer version of an electronic cash that enables payments without going through a financial institution.

it is "buying Biotcoins in cash outside a financial institution" that Apple reviewers deemed "reckless", not using cash "per se".

So I downloaded the app out of curiosity, and while the app advocates itself as anonymous or privacy friendly, first thing it asks you in the sign up process is your phone number, and then asks you to add your contacts, and later the whole mechanism of communication is basically based on phone numbers.. phone numbers aren’t secure, aren’t private, some countries even require biometric to register the numbers (aka SIM cards IMEI) and maintain a db of it [1], so why not just use texts at this point?! Even iMessage can use apple ID instead numbers now.

[1] https://www.comparitech.com/blog/vpn-privacy/sim-card-regist...

This feels very disingenuous - seems reasonably clear that the activity apple is concerned about is encouraging people to agree to meet strangers while committing in advance to bringing large amounts of cash.

Well it seems a PWA would be the best solution for you. Afaik Apple cannot block this (yet).