The interface is simple, it's easy for all caretakers to use (me, my wife, g-parents, etc), and it's a life saver when trying to remember when he went to sleep, how much he drank, when he pooped, etc. Our brains were so foggy we couldn't have survived without it. And the reporting features are super simple and informative.
We used CubtaleBabyTracker along with the cubs more than any other thing in our house besides our bed, couch, and phone. The cubs make it so nice to track without having to open your phone (especially important when you're in a dark room with a sleeping newborn). Now that our son is older, we still use CubtaleBabyTracker daily to track sleep and growth when measure him.
I cannot recommend the cubtale app enough! I'm also in love with the cubs, but I guess that's not what I'm really reviewing here. Lastly, I've heard good things, but I didn't try out any of the experts because it wasn't a feature when we needed them (which we definitely needed!! and wish it was a feature back then!). I'll update here if we try experts for any other reasons.