[Galaxy S 4 Themes and Apps] soraxd:
power toggles isn't needed, dropbar toggles are highly customizable.

picsay pro is awesome, might also want to consider this new kickstartr called Photoshop, its made by Adobe and is in the market for about the same price.

Desktop Visualizer is built into NOVA

really don't know what's special about MX video player, its less featured than stock, doesn't support. MKV files, and takes sooo much more out of the battery, not to mention uglier interface, no features, and loads super slow. if you want a dinosaur 3rd party video player use QQ, its chinese made so doesn't bother with things like licensing, and it'll play everything, even proprietary formats cause.. china ftw

home switcher is used so rarely, you might as well use the built in home switcher, under settings>apps

dropbox only if you already have it, otherwise use the 1tb dropbox destroyer Samsung included with the s4.

ES File manager .... let me share with you a proper file manager, Solid Explorer. every other file manager is the same except this one, multi pannels, drag and dropping, whole system indexing for instant search results, even includes your cloud drives (dropbox, gdrive, etc) and can drag and drop between them too.. most sophisticated file manager, competes even with windows desktop file manager.

too add to this list let me suggest a great pair;

BetterBatteryStats paired with AutoStart Manager. these two together can customly remove ads, remove battery drainers, mod features, remove trial limitations in apps, stop apps from starting up whenever tthey feel like it which is the reason you're losing 40% instead of 3% to standby throughout the day.

SMS Popup - if samsung doesn't offer option to keep screen off while getting notification, i suggest this. turn off notifications in messenger, and enable SMS Popup, i don't use the popup feature, but rather use it identically as stock, it brings up stock messenger, it only uses SMS Popup to notify (just without waking screen).

Titanium Backup, swiss army knife of android apps.

Thumb Keyboard. if you're not using Swiftkey to text like a maniac without needing to even look at your keyboard, then i suggest Thumb Keyboard. its an extremely comfortable hiiigghhlllly customizable keyboard, with a large split layout, or 13 other custom layouts, that you can tweak, has oh so necessary arrow keys, and test subsidies. to name a few of mine, i subsidize 'tue' for 'the' as built in dictionary will autocorrect it to Tue (short for Tuesday). i also changed 'khz' to '㎑' 'ghz' to '㎓', 'ducking' to '****ing' (lol..), as well as 'f3, f4, f5, and f6 to ( ￣ з￣), ( ´ ⌒`) (༯ ͡ ヮ ͡ ) (╥__ ╥╬)..

..anyways you get the idea.. you can replace any letter or longpress letters, and a zillion other features. just check it out.

QuickPic offers more photoviewing features, but ill admit integration with stock, and it's pretty ui are pretty awesome, so its your call.

same as above goes for poweramp, offers some better features, but ui is hideous compared to stock.

lastly i suggest you actually give the stock apps a chance before tossing them aside for 3rd party.. galaxy has come a long way since s1, at least give it a chance.