We released the calculator app “Calculator + 4”

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  • Download on the App Store
  • GET IT ON Google Play

Rooking Inc has launched a new App for iOS/Android.

■Calculator+4 Advantages

The first ever calculator to be able to calculate 4 things at the same time!?

Made with a minimal, sleek design and with large, easy to tap buttons.
Just turn the screen onto its side to reveal 4 calculators that can be used simultaneously.

[Major Features]

  • – Simple, easy to use design.
  • – Large, easy to tap buttons.
  • – When placed on its side, the app allows users to do 4 separate calculations at the same time.
  • – For portrait orientation, use the backspace key to delete the number.
  • – Percentage calculation function
  • – Vertical and Horizontal display compatibility
  • – In order to make the results easy to read, a comma (,) is displayed between every 3 digits.


  • – Basic math: +、ー、× 、÷、%
  • – +/ー Conversion

【Rooking Inc – Company Profile】

Location:3F Nakameguro TD Building, Nakameguro 2-8-22, Meguro, Tokyo.
Representative:Yudai Suzuki CEO
Established:8th August, 2012.
Content: System Engineering, Website Production, AI/IoT Design・Development, iOS/Android App Development, Server Support.  
  • Rooking Inc Corporate Site
  • https://www.rooking.co.jp/
  • Download on the App Store
  • GET IT ON Google Play