The GalleryNext app lets you view your pictures in one central location and also offers cloud service integration with Flickr, Picassa (G+), Facebook and Dropbox. The app will also include what CM calls Moments support, which is the grouping of media based on metadata. GalleryNext also includes support for video playback and for Gif files. And with Deduplication in "All" view, you won't lose available storage to duplicate content.
On the "to do" list are plans to implement "KitKat's immersive mode UI," and fix all of the bugs that beta users report. Speaking of which, if you want to test out GalleryNext, you can start the process by clicking on the sourcelink and following the instructions.
Screenshots from CyanagenMod's GalleryNext beta
source: +CyanogenMod via AndroidAuthority