Signal on Android has had reproducible builds for years now.

Sources: Github Readme, Official blog post

The ONLY data Signal stores about you is your phone number, most recent registration time/date and most recent login time/date. They don’t know who you’re messaging or when you’re messaging them AFAIK.

You can see this for yourself at signal.org/bigbrother

You can bridge your Bluesky account to the fediverse and all your future posts will be visible on the fediverse, though you’ll only be able to interact with people who have bridged their fediverse accounts back to Bluesky.

Did you mean Krita instead of ‘Keira’?