Android Screen Resolution

the problem am having is the different Android Device Screen size. when i lunch my project on to my phone it works perfect because i build it and test it on my phone, but when i lunch it to my Android tablet it does not fit the screen perfect has it did on my phone, i would love to know how to build one project to fit all android Device screen. if your guys can help me in anyway to fix t$$anonymous$$s problem and apply it to my project i would appreciate it thank you.