From my article "How to Avoid Funding the American Deep State":

'Since WhatsApp is owned by Facebook, and Skype is owned by Microsoft, I figured I'd simply refer to the Edward Snowden-endorsed, open-source, end-to-end-encryption-using messenger Signal, despite it requiring your phone number and access to your contacts. But then I learned, for example:

that Signal's developer, Open Whisper Systems, has received over $2 million from the U.S. government-funded Open Technology Fund

that Open Whisper Systems, collaborated with WhatsApp, Google, and Facebook to help integrate the Signal protocol into their messengers

that Signal (like many of the alternatives I refer to in this article) uses Amazon Web Services, as well as Google Play Services (if you have them installed)

and that Signal used the proprietary RedPhone server software until March 2017.

Fortunately, there's Tox. Like the Signal protocol, Tox is open-source and offers end-to-end encryption. Plus, unlike the Signal protocol, it's peer-to-peer (meaning it doesn't rely on central servers). The "official" Tox messengers also don't require your phone number or access to your contacts.