[rawfan]

I compiled Signal for iOS and monitored the sent data through a proxy. Both behave identical. There could be a hidden switch in the distributed binaries that triggers other behavior, but I really doubt it. For Android, there are reproducible builds so you can actually check the code is the same. For iOS reproducible builds are harder but should still be possible.

[squiggleblaz]

Can I verify that the build installed on my Android phone[] is identical to the one that I compiled? For instance, if I mount the device in Linux I can only see /mnt/sdcard, not /, so I can't copy the binaries off.

[] i.e. the build installed on my phone, not the build available no Google's server to download.