...connecting physical objects and smart mobile devices in order to stimulate and encourage imagination and creativity...

ABOUT Froxter


The idea behind the Froxter PlayKit is that children should play with physical tactile objects rather than being limited to virtual images on screen.

Simply put, it turns color and movement into structured sounds, thereby turning a mobile device into a sound-composing tool that is intimately connected to the use of hands.


We encourage children to instinctively learn about music by playing with geometrical building blocks whereby playing for fun becomes the source of learning and development.


Children with access to some type of "smart" mobile devices.

Froxter Playkit


A hardware set that augments the use of the application and the device


A modular application that connects physical tactile toys and smartphones.


A platform that promotes the collection and reuse of outmodelled devices for educational purposes.

  • Rather than focusing the game on the screen, the mobile device serves as a decoder of the art based education instrument that engages children in the process of creation by providing a playful haptic interface.

Tackle Set

The TackleSet contains the stand, mirror and the color chips. It also includes a detailed construction drawings of the stand and the puzzles so that the parents, if they wish, can build it for themselves.

How To?

1. Position the smart phone on a table or a floor, using the stand and the mirror from the TackleSet.

2. Pick a puzzle from the TackleSet and place it in front of you smartphone. The PlayApp will recognize the puzzle and take you to the matching sound engine.

3. Compose the puzzles pieces, move them around and listen to your sound composition.

4. Finally play back your creation to Mom, Dad or Friends!

Play App

A great way to discover the World of Music!

The Froxter PlayApp is a music app that gives young kids the opportunity to learn about and experiment with music composition.

We compare the experience to playing with Froebels geometrical building blocks. Here, kids can learn about music, create short musical compositions, choose different instruments and record the composition by simply placing the geometrical building blocks in front of the smartphone!

Building Blocks

Our Audience


Designed for kids from 2 to 6 years.

We also encourage parents and friends to participate and contribute to the children’s play. They can show their own composition and discuss what they can do together. They can even turn it into a duet, a trio, or even a quartet by playing color chips back and forth together taking turns. But the nature of the game is neither prescriptive nor rule-based. It is spontaneous and intuitive, encouraging discussions about “What if...”

Repurpose Hub

“To invent, you need a good imagination and a pile of junk.”

Thomas A. Edison

Many lower-income families can not afford the computers or mobile devices to help their children’s learning and development. At the same time, as the device manufacturers improve the design and market new models every year, old devices accumulate. An average user keeps a mobile phone for about 18 months before they buy a newer model.

The RepurposeHub contributes to bridging the inequality in access to and use of information and communication technologies.

We must repurpose and reuse superseded smartphones. It is a viable and necessary option to help bridge the digital divide by redistributing such superseded devices. But while general reducing and recycling has become popular, the motivation for repurposing and reusing dated smartphones has been overlooked largely because it is not profitable. The RepurposeHub will encourage and contribute to using older smartphones. It will also help redistribute and turn them into educational tools for children in need.


Why Froxter

Froxter PlayKit provides:

  • An effective tool to introduce children to musical tones, geometry, proportion, and color.
  • The potential for endless variations of play.
  • A balance between tactile haptic play and virtual screen-based play.
  • A socially conscious use of digital devices for children


Stefanie Holzheu

Stefanie is a native of Thuringia and studied architecture at the Bauhaus University Weimar. She produced a sound automaton and color-recognizing application for her thesis project. She is currently enrolled in the international Media Architecture Master Studies Program the Bauhaus University. She spent the last year at the State University of New York, Buffalo, where she created a story-telling smartphone application linked to specific geographical locations. In addition, Stefanie is a registered architect in the Netherlands, and received a start-up grant from the Netherlands Architecture Funds in 2010 for her study of the use of straw fibers. Stefanie has taught architecture and sound media at the Bergen School of Architecture, Norway, and served as a guest critic at TU Delft, Netherlands. Stefanie possesses working knowledge on programming and developing scripted websites and mobile devices apps, as well as designing, building, and programming sensor-based automatic devices.

Sang Lee
PhD., RA.

Sang is University Docent of Architecture in TU Delft, the Netherlands where he teaches architectural design and theory. He is a professional architect registered in the Netherlands and licensed in the State of New York, USA. He received his doctorate from TU Delft on architecture and media, “Architecture in the Age of Apparatus-Centric Culture.” For several years Sang has taught architectural design and theory focused on sound composition, performing arts, and public space. His primary research work consists of the relationship between vision and sound as the predominant modes of spatial perception, as well as the means of creative and experimental process. Sang edited and published “The Domestic and the Foreign in Architecture” (010 Publishers, 2007) and “Aesthetics of Sustainable Architecture” (010 Publishers, 2011) in addition to contributing numerous articles and chapters to international publications and conferences on digital media, music and sound, and architecture.