SimpleX is the gold standard here. Signal is mentioned here since they were the subject of Telegram's campaigns. I would absolutely suggest SimpleX above anything else.  

 @https://primal.net/e/note1vq9vwgpnypuxxn0233vyguttqz5dqnl6ctctunedeul2pgjvsqxs27w3gn 

 Well that didn’t work, is it like this?

https://primal.net/e/note1vq9vwgpnypuxxn0233vyguttqz5dqnl6ctctunedeul2pgjvsqxs27w3gn 

 Could you provide the link to the audit of SimpleX code your opinion is based on?