my apps are gone from my Samsung galaxy s3 tablet

I had my Samsung galaxy talblet s3 turned off for a while. In a few days I turned it bak on and all my apps were gone from my home screen. I tried to download the apps again but it said I have it alaready instlled. I looked in m files and my settings, but I couldn't find them. Can somebody please help me nd tell mee where I could look to find my apps. I wouldan be very pleased if you can fiveme answers.