How do you chart fertility

[Jrepp]

I currently use countdowntopregnancy.com and fertility friend, but might want to switch to something else. What websites, if any, do you use to chart fertility? What do you monitor?

 

[jelly tots]

I use ff and find it pretty good. Used to use countdown but didn't like it.
I like ones I can also use the app on my phone for, especially when away over weekends etc