My gui is super small on minecraft pe. I need help

I am playing on a Samsung phone for pe. When I first played it,the whole screen is small. The buttons and I tried to fixed it but never found anything. I guess it's the gui but there's nothing of a gui. When I play minecraft the crafting table/menu is small and it gets annoying. I just need it to be bigger because I so not have small hands. I domt know why it's like this. I deleted it 2 times and nothing,its the same. On my lg,its normal and fun. I need answers