Since your device is running a version of Android below "Marshmallow" saving things like Apps directly to the card isn't possible. You can move music, videos, photos, etc, over to the SD card and then will work just fine, and some apps (the few that can be run from a card), but most apps cannot.
To have an app run from the SD card it must be set as "Internal" rather than the standard "External". Only the newest versions of Android all for that.