Hello mjazjill.
I wonder three things: 1. did you inadvertently hide the app, as that feature is available to remove unneeded app icons from the app drawer, and 2. has your device received an update "OTA" (over the air) from your carrier or Samsung? 3. did a portion or all of the app reside in internal memory, or on the external, removable sd card? There is a possibility of corruption if it was on the sd card (not likely, as the sd card is generally used for media).
I'd try first clearing cache in the recovery area:
- power off the device
- hold three buttons at once: the volume up + the home button + the power key
- release them all at the same instant as soon as you see the little Android robot appear on the screen (right after the white "galaxy" logo appears)
- use the volume down key to navigate to "wipe cache"
- briefly press the power button to activate the wipe
- the "reboot now" will then be highlighted, press the power key for the device to reboot
That may remedy the issue. Let us know.