I have same problem. But my archive is off and was never on. I downloaded a bunch off apps and it changed. I can swipe delete, but there is no longer a delete button to hit after I read the email? Confused

My gmail on my iPhone 4S was working perfect.

I bought a iTunes card and registered it and bought some new apps

And tried many free ones. Now when I got to in box and read

An email the delete button option is now missing. I can swipe delete, and my archive is and has always been off.

At the bottom if the page on gmail on the phone the whole row of options delete, move etc

Is missing. Can anyone help?