Mail app with conversation view

I like the conversation (view by thread) view in Gmail, that includes emails I have sent as part of the thread. The native Apple mail app does not include my own sent emails even in threaded view. This means that if I want to refer to my own replies in a conversation I have to sroll down to the Sent folder, find it, exit it, then scroll up again.

in the Gmail app, my own replies are included, and the whole conversion can be reviewed in the one folder. But I don't like the font and the general look of the Gmail app as much as the Mail app, on my iPhone 6. I tried My Mail, which has a gorgeous look to it, but lacks this one essential (to me) feature too.

Is there an email app that has the look of the native app and the functionality of the Gmail app?

Richard