A very similar demo is available on the Tensorflow website, and the sources are available in the main TF repo. My sources will probably go public eventually.

https://www.tensorflow.org/mobile/tflite/demo_android

A web app could be done, but the use case and development process is somewhat different. The TFLite API is also significantly more mature. Looking at this TensorFlow.js demo might be helpful:

https://github.com/google/emoji-scavenger-hunt/

Send me an email at the address in my profile if you do anything with it - I'd be happy to help out with training!