A couple of immediate problems:
1) I am no longer able to visually distinguish folders from files, where did the folder icon disappear?
2) Swiping back is weird, sometimes it does work, sometimes it doesn’t. When it doesn’t, it either leaves me with a blank screen, or loads back what I just swiped away.
3) This really aggravates me, swipe back doesn’t preserve scroll position on long file listings, it renders the contents and scrolls to the top. This is really bad.
4) Where’s the footer?!
5) The whole thing just feels slow.
GitHub ui is getting worse on mobile as time goes. For example, why can’t I fork a repo from the mobile page?
I don’t know how you measure how your UI is used but I don’t think me browsing the code while sitting on the throne, or looking up a piece of code while laying in bed is so unusual. Maybe some of you should try that before such half baked stuff is released with much fanfare. Because the way I read it is “we’re excited to announce that we have broken your GitHub experience”.