Website View?

My fiancé and I both use homestead for business. I'm wondering if someone can shed some light as to why my sites will appear completely out of place on iphone, but android spacing is exact to my web builder and computer? The sites he makes on his laptop (the exact same way) look completely fine on android vs. iphone vs. desktop etc.  We've compared notes to see if maybe I am using features differently than he is and so on, and we can't seem to come up with any why.  Its mostly placing of buttons, pictures, text. I'll have to go on and respace, or correct text boxes, even though it's perfect on one phone or the other, or online in preview. 

Its really inconvenient to have to ask someone how the site looks on their phone before launching. It's not how you want to be doing business. Any ideas/answers?! Thanks in advance! :)