Support
Contact for the RYURAKU app
How to contact us
For questions, bug reports or requests about the app, please email:
FAQ
Q. Which devices are supported?
iPhone and iPad with iOS 15.0 or later, and Android 7.0 or later.
Q. Can I turn off personalized ads?
Open "About this app" (the ⓘ at the top right of the home screen) > "Ad settings" and choose "Don't allow" to get non-personalized ads. On iOS you can also use Settings > Privacy & Security > Tracking.
Q. Can I use the app with VoiceOver / TalkBack?
Yes. Actions done by tapping or dragging the canvas (adding vortices, pushing the object under, moving the obstacle or the hole) can also be done with buttons and sliders in the control panel. Each screen is described to the screen reader, and the ⓘ sheet explains how to try it.
Q. How do I go back to the default settings?
Tap ↻ (Restore defaults) at the top right of any simulation screen to reset its parameters and time.
Reporting a bug
Including the following helps us fix problems quickly:
- Device name (e.g. iPhone 16)
- OS version (e.g. iOS 26.0)
- What happened and how to reproduce it
About the app
RYURAKU lets you explore 12 fluid dynamics phenomena interactively: streamlines, Bernoulli's principle, Reynolds number, boundary layer, Darcy's law, vortices, the Kármán vortex street, lift, the Magnus effect, buoyancy, Torricelli's law and surface waves.
Version: 5.0.0
Pricing & ads
The app is free. There are no in-app purchases, subscriptions or paid unlocks. A Pangle banner ad is shown at the bottom of the screen.