App for raw files on iPhone 8

Just bought the iPhone 8 and looking for an app to shoot raw-files. I want to be able to adjust ISO, shutter speed and aperture. Also if possible release the shutter with the volume buttons on the side of the phone. Any recommendations?

I also would like to have some kind of histogram(preferebly RGB) showing.

I am trying the Flannl app right now. Easy use but I cant get slower shutter speed than 1/4s. Not possible to go slower then that with iPhone camera?

Have you tried Lightroom Mobile?

Thank you. I have download Lightroom Mobile and this is the best camera app I have try so far

The only feature I miss is longer shutter speed(slower tahn 1/4s) but maybe it is not possible for the iPhone camera?

Camera+ can go down to 30secs, shoot and edit Raw and even takes advantage of Portrait mode if run on the 7/8 plus.
I love Lightroom Mobile but as a camera its not up there with the better dedicated camera apps IME. The two together make almost a complete mobile workflow.

Camera+ is the best app so far and I will stick with it as main camera app.

One thing I noticed is that raw is disabled below 1/4 seconds shutter speed, thats a bummer.