Refactor `screenSize` to be a property
Refactor `screenSize` to be a property

seanwoodward/IBAnimatable,seanwoodward/IBAnimatable,JakeLin/IBAnimatable,IBAnimatable/IBAnimatable,IBAnimatable/IBAnimatable,JakeLin/IBAnimatable,alexiosdev/IBAnimatable,IBAnimatable/IBAnimatable,alexiosdev/IBAnimatable