"Nowadays I'd expect a secure messaging app to not just be open source, but also have reproducible builds (checked by third parties). " Alternatively, they can

"Nowadays I'd expect a secure messaging app to not just be open source, but also have reproducible builds (checked by third parties). " Alternatively, they can make it paid, shared source to allow inspections while simultaneously making money. If aiming for contributions to paid source (eg bug fixes or feature improvements), they can make the licenses irrevocable per version with the OS interfacing parts permissive, open source with allowance to swap them out as desired. So, the old version could be updated legally for new platforms giving potentially, perpetual ROI. People wanting upgrades or security fixes have to buy the new version or maintain a subscription. I mean, nothing would stop people from just doing that themselves with the source shared. I just figure lots of paying customers will stay paying customers switching for reasons having nothing to do with source license. They move for all kinds of non-security, non-philosophical reasons.