Uninstalling Flare Effects
How do I uninstall the Flare Effects photos extension?
If you wish to simply disable the Flare Effects extension, but don't wish to delete it, you can do so from within the edit mode in Photos.app. Simply open that view, tap the ... button to open the Extensions panel, tap the More button in that panel, and then switch Flare Effects off.
If you wish to completely remove Flare Effects from your device, simply delete the Flare Effects application from your hope screen.