While reading this review, keep in mind that this is a commercial for a mobile app and is not in any way to be taken as a anime series or OVA.
It's cute, and gets the point across with nice visuals and a really adorable song - I'm not sure what the product is that their advertising, but that's okay, I wasn't interested in it any way.
Story: There really is none, as it's simply a commercial about a cute anime girl and her phone. So, I'll give it a .. 7.
Art: Good! I thought it was cute and simple, and got the point across fine.
I really liked the music, it sounded like something that you'd hear at the beginning of a Shoujo or Slice of Life anime about high school girls, or something of the sort.
Overall, I'll get it a 7. It was cute, simple, and if I knew Japanese I probably would've been sold on the product/game.