If the App is free, you are the Product!

Please check:

https://SecureMessagingApps.com

+ rate
🟩=3
🟨=1
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Results =

86 Threema = most secure Messenger

78 SimpleX Chat
76 Session
76 Signal
66 Wire
55 Element / Matrix
36 Apple iMessage
26 Telegram
25 WhatsApp
25 Facebook Mess.