I use the term FLOSS (Free Licensed Open Source Software) because it points out the license and it is a preexisting word.
In theory, as well as reality, the code running is possibly not the same as what is stated. The GPLV3 makes an appearance here as it requires AGPLV3 code for legal use. Supply line and obfuscation attacks don't mind either way.
Signal is the best way to use a smartphone.