I glow, flo and recently found out a new one called Premom developed by Easy@home. Glow has too much information and flo is more like a <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a>. Premom is great since it has the ov test gallery allows you to upload your tests. My O prediction from those 3 apps are kinda similar, I normally would double check with all of them just to be safe. What's your favorite <a href="https://play.google.com/store/apps/details?id=com.glow.android">Ovulation app</a>?