There are, very good ones, but they split into two groups. On the one hand, you have the apps built by the large corporations - Messenger, WhatsApp, Skype. Each claim your data is secure, is encrypted, yet you receive adverts that relate to the conversations you’ve had.
On the other hand, you have apps like Telegram and Signal. They’re good, they’re secure, but built around the needs of the individual, not the organisation.
Semafore is different. It’s highly secure, built by independent cyber-security firm Attomus, specifically built to meet the needs of the Enterprise.