DON'T WASTE YOUR MONEY ON THE APPS!!!! All you have to do is pick your picture in your camera role and look at it vertically, then tilt ur device so it shows up horizontally then screen it. When you look at the picture that was screen shot it will work. Trust me! Not waste the money!!!
Sure. Any app or process will that allows you to a) save on a square background (like PicBoost), or b) Re-size Canvas (like Filterstorm, where you'll give it a 1:1 aspect ratio, like "960x960"). PicBoost's backgrounds are limited to black and white--white being useful for IG since IG's background is white, and reads as being "clear". Filterstorm gives you an RGB/Spectrum picker for any color.
I had the *exact* same problem, but also wanted a simple app that I could upload lots of pictures in just a click or two & do it straight from my phone's camera. I couldn't find one so I made one, called it "Easy Square" --