Three years and still waiting!!! Want advise on a pool app

I signed up for the forum three years ago and still have not been approved. I'm going to guess that nobody is in charge here. Ben must be gone forever.

I wanted to ask for advise on what app to buy to for my iPhone. I wanted to see if there is a certain app that uses the BBB method and shows how much bleach I need to put in my pool to keep the fc around 5ppm. I saw it one time but I can't find it.

Thanks!