When you're finished you'll be able to search for a tag to get all the photos which have that tag. QuickPics has a button in the lower left of your library to display all the tags you've created and give you an alternate way to search your photos.
In the Tag list, you also have the option to select groups of photos with a specific tag so you can share all the ones that have a specific person or surround a specific event.
Location, location, location
As I said above, the thing that QuickPics lacks is the ability to show the location of your photos. Using the iOS photo library, you can browse through Moments and touch the city where a group of photos were taken to bring up a map. From there, you can browse the map for other photos by location.
If QuickPics had the same capability it would be hard to find an argument for not using it as a complete replacement for the iPhone photo library. Without locations, QuickPics is great for searching and sorting photos, but feels like its missing a key feature.
QuickPics is excellent for finding specific photos once you've put in the work. Adding tags and photo names makes it incredibly easy to zero in on the photos you want without scrolling through a seemingly endless list, like with the iOS photo library.
The one thing it's missing is the ability to find the locations of photos, or to sort by location. Adding location would give you yet another way to search for photos and because I'm used to using the feature in the iOS photo library, I find myself missing it in QuickPics.
Still, once I tagged my photos, I couldn't believe how easy it was to find specific shots just by remembering who was in them, or the event where the pictures were taken. If you don't mind a little work to get PhotoPics set up, I think it's an excellent way to manage and search for photos that's better than the search features iOS has to offer.