From the comments:

This is idiotic. Signal didn’t take money from the NSA, they took money from the Broadcasting Board of Governors, which funded virtually all Internet privacy projects during the time period we’re talking about, both American and otherwise; some of those dollars went to development, and still more went to contracting commercial pentests from firms like Matasano, the one I co-ran, and iSEC Partners.

This article says it’s not rehashing DeVault’s arguments, and it isn’t; it’s making an even dumber set of arguments.

Stoped reading after “it’s on f-droid” he doesnt seem to have a clue what he is talking about. It would have taken like one minute to check this. Signal is not on F-Droid