What you need to Know Before Developing for Google Glass
Recently R/GA’s Prototype Studio launched a bikeshare app for Google Glass as an internal project to explore and understand the Glass product and platform. Along the way we learned that developing for Glass is not at all like developing for mobile.
With Glass, Google released the Mirror API—currently the only Google-approved means to build apps for Glass. The Mirror API is very strict in terms of look and view, and only offers a few simple UI elements and interactions. Many developers will have to adapt to Mirror’s much narrower set of options. Below are some of Glass’ limitations.
No voice commands, such as responding when the user says “OK Glass, open <My App>.”
No applications installed directly on the device. The Mirror API expects you to build a backend service based app, which pushes screens to the Glass.
No response to custom physical interactions, for instance double-swipes on the glass or head shaking.
No augmented reality functionality, such as detecting where the user is looking and overlaying and enhancing it on the Glass screen.
No real-time location detection. Currently your app gets updated of the user’s location every 10 minutes.
No overt advertising. But having a branded application that offers some utility to the user seems to be OK.
No app store (yet). You can have people install your app via a shared URL. They can use it up until the 1000 daily API limit is reached.
So what can you actually do with Glass?
A Glass app pushes HTML “cards” to the device, respond to clicks on the menu items within the card, respond to location updates from the device, and accept images/video/text that the user shares with the app. These limitations will almost certainly affect your app’s user experience. All these elements are described in the Mirror API documentation.
There are ways to flout the Mirror API and hack the Glass to do essentially whatever you want. There is zero documentation or support from Google on how to do this so you need some serious Android hacking skills. But, even If you are able to figure it out there isn’t an easy way to distribute it to users. Users will have to root their device to install your app manually.
The quickstart applications that Google provides provide a great way to get up and running quickly. They come in Java, PHP, and Python flavors with all of the authentication and endpoints setup for you. App Engine is an easy deployment option for beginners.
You don’t need Glass to develop an app.
Luckily we have 3, but if you don’t you can setup the Glass API keys and develop through the Glass developer playground.
Google appears to be very committed to getting their Glass product off the ground. If history is any guide, Glass will only improve. Despite its limitations Google Glass and the Mirror API offers an exciting new way to bring technology into our lives.