Depends on what you need. EFF previously used to have a scorecard[1] for all the messaging applications, but they reconsidered the model of their recommendation and put together a good set of articles on the topic which ask questions to consider and provide privacy and tech context. Here's one: https://www.eff.org/deeplinks/2018/03/thinking-about-what-yo...

The rest are linked from here[2].

[1]: https://www.eff.org/pages/secure-messaging-scorecard

[2]: https://www.eff.org/de/deeplinks/2018/03/secure-messaging-mo...