Spellbinder2 - Visual Graffiti hack for OTA12

I had a fun weekend at Beltchley Park taking part in Over The Air. There were plenty of interesting talks as well as a 24 hour hackathon to create an interesting mobile app/service over a variety of categories.

In my day job at Mobile Acuity Ltd. we regularly provide large scale mobile visual search services over a range of customer provided media. I was interested to look beyond that and explore how visual search can be used to form a bridge between objects that people encounter in the real world and the digital conversations about those objects.

This is not an entirely new idea, and in fact Mobile Acuity was formed off the back of a project called Spellbinder which set out to provide something similar using MMS prior to smartphones coming on the scene.

Modern smartphones provide the opportunity to do something similar but with a much lower friction experience for the end user, and so I decided to create Spellbinder2 based on a combination of an Android app and Mobile Acuity’s image search backend.

The concept is visual graffiti - allowing the user to leave digital graffiti on any object they wish, which can then be discovered by the next user who looks up the same object. To keep things simple it only allows a single graffiti on each recognized object - and thus only allows graffiti to be added to objects that it doesn’t yet recognize.

If you want to try it out you can download the app (Android 1.6+ only) from:


The best way to install it is to allow installs from untrusted sources and then enter that URL directly into the device browser.

Once you have it installed select something nice and recognizable (flat-ish and relatively high detail) and take a pic of it in the app. If someone has already added graffiti the app will display it blended over the image, and otherwise it will allow you to add your own. It should work nicely on most print media, boxed products, books/CDs/DVDs and similar.

Have fun and let us know how you get on,


PS. Caveat emptor - this app is provided purely as a toy for interested folks who saw or heard about my OTA12 presentation to play with, and both the app and the visual search service behind may be withdrawn at any time at Mobile Acuity’s discretion.