Understand first of all, that like many of this type of game, the download is basically a demo. When you see the notation that there are in-app purchases available, look in the app description for the list of available purchases. That will allow you to go in with a better idea of what youre in for before downloading it.
I personally dont mind this setup because it allows me to gauge whether or not my child will enjoy the game long-term before I make a commitment to buy it. (And app development isnt free, after all, so income usually has to come from a paid app, ad sales, or data mining. For my kids apps, Id prefer a paid app model over the other two options.)
This game allowed enough play in the demo mode that I could easily gauge her interest, without it being too naggy about buying the upgrade. (Some demo apps really push the purchasable stuff upfront so the child is drawn to it, while in this demo the free characters were the more natural first selection.)
The app itself is really enjoyable. My 3-year-old girl loves it. There is a good variety of play. You dress up the girls in outfits/hairstyles, change colors and textures of the clothes, and play mini-games. There are the six (?) main characters and each can play one of the six different scenes (each scene has its own outfits, hairstyles and mini game).
Through playing the mini-games you earn additional prizes (outfits and hairstyles), which will allow the game to continue evolving for quite some time. Im sure it will get old to her eventually, but for the price of a couple of dollar store toys, this is going to last a while.
Age-wise, I think it is probably perfect for 2-6 year-olds. For a young 2yo some of the mini games might be a bit tough, and for an older 6yo, the play might get repetitious fairly quickly. 3-4 is probably the sweet spot here.
My only real complaint (and reason for 4 stars rather than 5), is that they do push their other apps with a big stamp-sized ad on the home page. I have no problem with them promoting their other apps, but in an app designed for preschoolers I would rather it be a little more subtle.