The vision here is satnav for pedestrians. Given a route (potentially just a GPX file), it would:

  • Show it to you on a map
  • Tell you where/when to turn
  • Include a “background mode” that would vibrate/ping you when you need to turn, or when you’re off course
  • Show nearby services

Could be fed by either raw GPX, GMaps walking directions (I’m assuming the APIs are compatible), or GPX + auxiliary data. This last case could involve things like written directions (Turn left on Oak Street, go through the hand gate, etc.), specific nearby attractions (restaurants, bars, hotels, …), or whatever. They’d either be tied to specific points in the directions, or just geolocated so the app could show & tell you about them.

So initially, this app could be fed both by existing crowdsourced GPX repos, and by GMaps directions. For directions augmented by aux data, this could either be crowdsourced again, or could come from professional writers in the form of an e-guide that you’d buy and download. For the crowdsource option, I envision it being run quite like an app store; essentially anyone could register as a “publisher”, upload e-guides, set a price, and sell them. Buyers would get to rate and comment on them.

Target markets would be hikers, as well as pedestrian travelers of any sort. [Visiting Munich? Buy the e-guide to the best beer halls!]

From a tech side, it’d require:

  • A good mapping app, including offline maps – for use in the backcountry, or foreign locales – as well as a selection of different basemaps (GMaps, OS, USGS Topo, etc.). It’d also be cool if it had some high-contrast option for better direct-sun readability.
  • The various navigation modes. Background mode seems particularly interesting, because you’d want it to work something like: wake up every 5-10 minutes, get a quick GPS fix, make sure you’re still on course, then go back to sleep to save battery. Wake time could be adaptive, so it’s awake more in the vicinity of turns you need to take, for example.
  • The e-guide store, perhaps just in the form of a mobile-optimized website. This store should also be accessible from the desktop web, including:
    • facility to buy e-guides and send to a registered device. As a first step, this could just be an email with a clickable link to the download
    • management of the e-guides you own
    • publisher tools (especially if we go the crowdsourced route)
  • On-device management of e-guides

Could the on-device client be built entirely as a web app? Possibly, but this introduces additional challenges, like offline storage of maps & routes, and fine-grained control of GPS. I don’t know that a web app can set an Alarm in Android, for example. Might make the most sense as a hybrid app; do some bits in HTML5, for easier portability, and then code fully native bits where you need to. And yes, this one really should be cross-platform, not just Android.

But I also have this vision of a hardware aspect, running Android (of course), as the Kindle to my e-guide books… I see a waterproof/semi-rugged device with a 5-6″ daylight-readable screen, and packing enough battery to run GPS+Glonass for 10-12 hours continuously. Heck, my ForeRunner can do that, why can’t a phablet?

Even if I don’t do my own hardware, there definitely seems like an opportunity to pitch it for OEM inclusion on devices like the Motorola Defy series.