I use Clue and will recommend it when the time comes to DD. If she takes after me and my mom she will be blessed with feeling ovulation pain, which you can enter in the tracker which then helps better predict the first day of her flow. And given the other thread talking about first periods being all over the place in terms of length and frequency, I would think that tracking might be helpful.
Mom to two amazing DDs ('07 & '09) and a fur baby.
Gluten free since Nov '11 after non-celiac gluten sensitive diagnosis. Have had great improvement or total elimination of: migraines, bloating/distention, heartburn, cystic acne, canker sores, bleeding gums, eczema on elbows, dry skin and scalp, muscle cramps, PMS, hair loss, heart palpitations, fatigue. I'm amazed.