Glow vs. fertility friend

C 💕👌🏻✨🍍👶🏼🤷🏼‍♀️

I read that some of you use FF for charting and find it more accurate. I got the app and plugged in all of my info. Glow is saying I'll O on Saturday 8/5 and FF says Friday 8/4. I'm using OPK and temping buuut, I'm just curious for those of you who have used both apps for a while-- which one would you trust more and why? Thanks girls!