For those unaware, you swipe to access voting/reply on comments, swipe from left to right on a comment to get to the up/down vote and swipe right to left to reply.
On your inbox, you can mark replies “read” by far swiping right to left.
You can also swipe to go back to your feed back swiping left to right starting from the edge of the post.
Lastly you can access settings by clicking the “gear” icon in your profile screen (top right)