only in windows 8 / windows 2012 server while i'm looking into this folder, why every time an application gets an updates, they make another copy of folder, with different name (same application) i think it's very inefficient, due to space consumes... here's the proof. note : by default you cannot see / access folder "C:\Program Files\WindowsApps" you need to take ownership of the folder to see inside. or you can use Ubuntu Live CD / Hiren
Windows Apps are far from efficient, it's definitely not a platform that you could use for all your computing needs (word processing to graphical design and full featured games). It's not download friendly either, so if using it on a mobile device you better make damn sure that you have the data bandwidth through your phone network provider (if this is how you are connecting). Windows Apps aren't space friendly, and they seem to include a considerable number of files. The system isn't well conceived, and has been said time and time again, 'one size fits all' is a stupid approach and the ONLY reason why we're stuck with a crappy UI etc is because Microsoft reckons it will help sell more Surface tablets.