The latest update for the Google Photos was announced at the Google I/O keynote on the 28th May 2015.
Things have changed quite a lot, especially the editing (create Stories from scratch) and sharing. You can share directly to a social network, or choose Get shareable link to send someone a link.
The desktop functions very much like the mobile app.
Now it is very important for you NOT to delete any photos unless you are very sure of what you're doing and where you are deleting them from.
Especially Blogger users, hey! Your albums are very well hidden on the app, at least for the moment I could not find mine. Luckily there's still the desktop and the old Google+ Photos.
Remember: All your Auto Backup photos and creations are private and visible only to you until you decide to share them!
Chromebooks will lose the Google+ photos app on the 21st July 2015.
I'm sure there will be more development: Make sure to send Feedback to Google with your wishes and concerns.