iPGMail

Works, not really user friendly but once you get the hang of it, it is ok.
Biggest problem is that it refuses to work with LastPass. When LastPass enters the password, message decrypt of key import doesn’t happen.

Gecodeerd en ondertekend email van en naar je iPhone! Volg gewoon de instructies in de App.

Works well! Would be nice if I could save my signature though for composing mails.

It takes some time to get the private keys imported, since the feedback is unclear. But when taken that hurdle this app just works as expected. This is the only pgp/gpg app that I found that is free, working and regularly updated. Good!

Works great with the default iOS mail app (still some copying here and there) but nothing too complicated.
One thing I miss is the ability to import public keys from the clipboard. This works best for people who share their public keys outside of a central key server.

Import causes crashes, but after restart import is mostly decrypted. Unfortunately signatures cannot be verified.

Importing
existing keys proved to be non-intuitive. Instructions in the website did not bring any relieve. Come on, guys, give us a step-by-step instruction with pix and/or a video.