Google Plus developers have delivered another update today. This one is aimed at making tagging people in photos easier.
Google Plus Albums how has a special section where it shows all the faces categorized together so that you can add names to faces easily.
Uploading newer images would highlight this section automatically so that you can quickly tag all the people featured in that album.
Tag people option is also accessible from a shared post.
And you can access the same option from existing albums.