I currently use all 3, I had NC first, then I downloaded premom for the OPK analyzer, then somebody told me FF was better for charting BBT.
I realise this is overkill and silly to have all 3, also they all have slightly different predictions and make it difficult to know which day is ovulation day as they are all slightly different.
which one do you find the most accurate. PS I no longer BBT as I couldn’t commit. I want to just stick with one to avoid confusion going forward! TIA x