I can't figure it out! – Font Infinity ∞ Cool New Fonts Changer and Better Text Styles on Pictures & Photos Review

I think its a great app, with many fonts to choose from, but it won't let me use the fonts on Instagram. I tried to use the fonts as told, but Instagram isn't even 1 of my choices. I even watched the "How to use" video, but it still didn't help me.
Review by Country chic? on Font Infinity ∞ Cool New Fonts Changer and Better Text Styles on Pictures & Photos.