The NSA's BULLRUN program suggests that the TLS encryption is compromised anyway. My money is on certificate authories having given the NSA a backdoor 'for national security'. I don't think that they need to compromise an app directly.
If you need to communicate privately, please don't use an open forum. Use an OS without telemetry (not Windows), make self-generated keys for GPG emails or OMEMO chat, and verify the key signatures directly with your comrades. If you need to communicate anonymously, bear in mind that there is no silver bullet.