SimpleLogin is hosted with Protonmail and should be viewed as an extension of it.  Proton cooperates with thousands of law enforcement requests and should be viewed as a corporation and not a just open source software that’s just code.

On the other hand, AnonAddy has a better UI, better reputation, seems like just 1 developer which is more hipster, Greenhost is a more trusted host by me, and is more representative of a FOSS project.  You can self host it, and F-Droid has apps for it by different random developers.  SimpleLogin uses Coinbase as a crypto payment provider, which blocks Tor and is going to get the transaction run through an anti-fraud (and therefore anti-privacy) surveillance tool.  

I do not support crime, I but do support a decentralized internet.  Protonmail & Coinbase are more centralized than a lone hipster with Greenhost and Globee.