This app was mentioned in 2 comments, with an average of 1.00 upvote
Here is the original photo gallery app with no Google sync and no ads either. https://play.google.com/store/apps/details?id=com.moblynx.galleryicsold
For offline music, try Musicolet. Again, no cloud, sync or any ads
https://play.google.com/store/apps/details?id=in.krosbits.musicolet
If you liked the gallery from Ice Cream Sandwhich (which I do), there's Gallery ICS (classic version) on Google Play, without ads and pretty much same as the stock gallery from 4. They also have an updated version with more features, Gallery KK, but that's a pay-for app, and comes with ads unless you pay, but many of the new features are quite nice.
Never did like the new Google Photos app. It stopped showing several folder drivers after an update, and I just missed the old viewer from 4. (Just like I miss having a screenshot button at the bottom on my toolbar—I'm wearing out my volume down button!)