It's an Android emulator that you can install on a computer. When you launch it, it will open a window with an interface that looks like the interface of an Android phone (with a Google Playstore button, etc...).
Here is the link to their official website if you want to know more about it :) https://www.bluestacks.com/fr/index.html
I feel like you'd like the game Time Princess. That's the first style you unlock :)
Almost forgot to mention Helix Waltz. The costumes are nice, but I quit due to low space on my phone. Maybe it would interest you until SN comes out?