Feedback App


The Feedback model app generates a dynamic block model diagram representing cybernetic systems, on which the input value, block values and disturbance value can be altered. This allows you to see, in real time, the output of the system. The type of feedback in the system being modelled is shown at the bottom of the screen.

Dynamic graphs are generated. By changing the settings, the type of input used to generate the graphs can be switched between using straight input to generate line graphs, or using sinusoidal input to give dynamic sine graphs of both the input and output. By using intuitive gestures, you can easily manipulate the graphs, altering the frequency, phase and amplitude.

This application is intended for use alongside appropriate reading materials on the subject of Cybernetics to aid in understanding block systems. It serves as a brilliant revision tool when dealing with questions on feedback block diagrams.

All suggestions are welcome to help me make this the most useful application possible; please either leave feedback via the app reviews or by filling in the fields below.


Version 3.0.0 of the Feedback App has been approved and is now live on the App Store! Also Version 3.0.0-beta is now live on Google Play! - 18thSeptember 2014

Version 3.0.0 of the Feedback App has been submitted to the App Store and is pending review. This update should be released on the 17thSeptember, ready for the release of iOS 8. - 11thSeptember 2014

In version 3.0 of the Feedback App models are now loaded dynamically from files. This means adding new models to the application is far simpler than before. The new and updated app engine can model a multitude of different types of feedback system, including more complex systems. This is achieved by modelling parts of, or entire systems, as a single embedded model block, allowing more complex systems to be displayed on a smaller screen, without losing the ability to alter parameters or view all blocks that make up the system. - 30thAugust 2014

Major updates are coming in Feedback version 3.0! - Development is currently underway and things are looking good. This version not only brings major improvements but also will be made available on Android. Full details of what is included in version 3 will be posted closer to the release date. - 30thJuly 2014

Feedback has been updated to use iOS 7 GUI elements. Updates are planned for the iPhone app, including adding more types of feedback model to the existing basic model. Look out for these changes in version 3.0


As you may have noticed the site has changed, but the support for this app has not. If you have any comments, suggestions or just need some help please use the contact form to send me an email and I will get back to you as soon as possible.

Change Log

New Features in 3.0.0 (Current Release)

For version 3, the app engine has been completely re-designed from the ground up.

  • Feedback models are now generated from a file
  • Multiple models can now be viewed on the iPhone version of the app by clicking the embedded model block to view and change an embedded model.
  • The input type for the graphs can now be altered in the app settings (From the settings app)
  • Bug fixes make the output value more accurate, preventing decimal cropping that was previously occurring.
  • Systems with embedded models can now be modelled.

Note: Some of these changes only apply to the iPhone version of the application currently. A future update will bring them to the iPad version.

New Features in 2.0.1

Features Introduced

  • GUI redesigned for iOS 7
  • Built with support for 64bit iPhone
  • Swipe gesture to return from graphs on iPhone

Bug Fixes

  • General bug fixes

New Features in 1.3.1

Features Introduced

  • New section on calculating the output
  • Highlighting of Forward and Loop devices (iPad Only)
  • Labels now shown on the output vs disturbance graph

Bug Fixes

  • Spelling issue fixed
  • Minor improvements

New Features in 1.2

Features Introduced

  • Feedback type is now calculated
  • Graphs of both input vs output and input vs disturbance are now generated
  • Tapping on the input and disturbance labels resets their respective slider and value to zero (this can be useful!)
  • The iPad GUI is now included, with a second feedback system modelled
  • "Learning Mode" for iPad can be turned on in the settings, requiring the user to select if the feedback is positive or negative

Bug Fixes

  • A rotation issue has been resolved for iOS 6
  • Minor enhancements for compatibility with iPhone 5 display