Re: why does app not dowload, says insufficient space on device
Apps download to the internal storage by default first and there's no way to change that. If there's not room on it, there is no option to download directly to the external card. Also, not every app can be moved to the SD card, and those that can may have different amounts of data that can be moved.
So the best thing to do is move your media and any other files you want over to the new card so you can free up space on your phone for the apps.