Checkmates: a mobile friend finder prototype for eTech

I’ve been working on a project recently that is really the convergence of everything I love about my work these days: promoting grassroots innovation at Yahoo! through events like Hack Day, building cool stuff, and trying to glimpse the future through prototypes that reach a little bit. (Aside: I just noticed that in Jeremy’s original post about Hack Day, he called it the first “annual.” We’re doing them quarterly, and in fact, we’re doing another one a few weeks from now. Can’t wait.) What I’m writing about today is actually the result of Ed Ho, Jonathan Trevor, Karon Weber, and Sam Tripodi’s “failed” Hack Day project. At the end of our first Hack Day, Ed, Jonathan, Karon, and Sam had nothing to show but ambition, but the experience lit a fire that resulted in something really cool that we can now share.

I’m referring to CheckMates , a prototype for telling your friends where you are and seeing where they are on a map (i.e. check your mates) — on your phone. It wasn’t even close to working at the end of our last Hack Day, but it is now. You can download it now — just click on the Install link on this page and follow the instructions. One note: since this is a limited-release prototype, we’re capping registrations, so the downloads will pause at some point. There are a couple other disclaimers.) This prototype was built all on public Yahoo! APIs, so we’re also hoping that it will inspire you to build your own stuff! Theoretically, Checkmates should work on any Java/MIDP2 capable phone but it’s known to work on Nokia Series 60 phones like the 6620, 6670, 6680, 6681, 6682, 7610 models, and it is likely to work on 3230, 6630, 6260 as well.

Mapping on a phone certainly isn’t anything new, but when you overlay a social network on top of the mobile mapping experience (in this case, your Flickr “friends and family”), it gets really interesting. When using the Checkmates prototype, you’re able to see your friends’ locations, what their status is, and when they last broadcasted their location (assuming they are also using the app).

Aside from pulling your social network into the mobile mapping experience, Checkmates takes things a bit farther — it takes you inside the building and lets you track your friends when you get there. Think of it as an additional zoom level, jumping beyond street level into a building or other space.

For this prototype, we put a map of the eTech floor into the app, but the mechanism we used (the Flickr API) to do that means that the possiblity exists to spontaneously map a world of semi-public and private spaces that have been unexplored up to this point. Imagine going to an amusement park, taking a photo of the map at the front of the park, then using that map immediately within an intuitive and easy-to-use mobile mapping application to track your friends and family while you’re there. Not to mention that you could share this map with other people who might need it after you. Cool, huh?

This prototype is so fresh that the URL for it is ugly (sorry about that — here’s a tinyurl instead:, but we wanted to get it into your hands to play with it despite a few rough edges here and there.

There’s a lot going on within Checkmates, so check out the page that explains how to use it and the FAQ.

If you want to let the team know what you think, email us at techdev-feedback (at) Remember, this is just a prototype and as such, has no support — but we still want to hear how you’re using and how you would make it better. We hope you have fun with it!

Update: Ed writes more about the inspiration for this, and Jonathan adds his thoughts.

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8 thoughts on “Checkmates: a mobile friend finder prototype for eTech

  1. Great idea – wish I had something better than a Treo to work this on. This gets really interesting if we overlay this concept on a workgroup and/or casual connections can be mapped at a social gathering – ie, a way to bring about a Nintendogs like meeting between 2 or more people through our phones.

    Could also be applied to a confernce situation where there could be a quick bluetooth ack sent back and forth to add people you meet to a temporary social network, so you can find them later if you have something else to share with them, or if you want to introduce them to someone else…

    So many other potential uses in this – I am just glad to start seeing real location based apps in the hands of real users instead of in the lab! Congrats to you and the team!

  2. Hi
    The interface looks neat. Could you please tell me how you implemented the pie/radial menu in J2ME?


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