I moved some apps to SD, why haven't int/ext storage changed?
I don't want to sound bad or anything but the above linked question still applies....
Really to save space you move things such as photos, videos, music and films to the SD card (This can be done via in app options normally such as within Google play music settings -> manage downloads -> internal / sdcard).

However some apps do store data on the SD card. One such example is a ringtone app. So when you download the ringtone its saved to the SD card. And some games save stuff to the SD card. So you may end up saving a bit of data here or there.

It really depends on the app as the APK's themselves can be quite large and are stored in the system memory rather than the SD card which also has limited permissions too which is also another reason as to why some apps won't move to the SD card.