It's playable on Android.

Finally, it's playable on Android.

To tell the truth, I was totally new to the development of web apps.

So, I didn't know the convention of the web sites development

 that generally fonts are processed to reduce its size before 

served on the web site. 

Also the process of compression was applied to all its PNG images.

Now, I confirmed the app is playable on Android devices.

Especially, on android 4.1 and above.

I wished to make it run on old devices like android 2, because I've heard

that many children are given old devices from their parents. 

But sadly I found the fact that browsers on those devices aren't compatible 

with the Javascript technology of my app. But once you learned the way of

calculation with my app, you don't need actual devices anymore.

Anyway, please use this app as a time killer in a break anywhere at any time

to improve your calculation skill.