Poor wifi signal in bedroom. Opinions on best options? Prices

I have verizon fios. Router is at the back of my apartment on the 2nd floor (living room). My bedroom (where the poor signal is) is at the front of the apartment on the first floor.

I spend a good amount of time in the bedroom watching videos and whatnot on my ipad and iphone. Trouble is I often get stuck using LTE due to poor wifi signals. Which then uses up unnecessary data on my mobile plans. Also extremely frustrating trying to watch something while the device toggles back and...

Poor wifi signal in bedroom. Opinions on best options? Prices