Cacher's Apprentice

After getting excited about Mologogo, I broke down and bought a cell phone. Then, being a geek, I went out and started reading up on J2ME, the development system for it that would allow me to create my own applications to carry around with me. Then, still not having filled my nerd quota, I got to thinking about what sorts of interesting apps would be enabled by the combination of GPS and web access in a mobile device. By this morning, I had worked up the following application design (mostly in my subconscious while sleeping). I’m excited about the idea; if you’re interested, please feel free to chip in ideas. If I get around to coding, the current plan is to make it open-source so other people can help with the hard math. 🙂


Cacher’s Apprentice (working name) is a tool for geocaching from a mobile phone. It will provide facilities for locating nearby caches and for helping the user to find them. There will be an operating mode to support each of these tasks. (Note: doesn’t provide web services currently, but does have a lightweight interface that should ease working with their site a bit, though it still relies on session data more than would be ideal.) The ideal user is someone who enjoys geocaching and is traveling, finds herself with a bit of spare time, and wants to see if there are any caches nearby to seek out.

Location Screen:

  • When started up, application will be in location mode.
  • App will query the GPS receiver to get current location.
  • App will then query with the current latitude and longitude to find the 10 caches nearest the user.
  • Caches will be displayed in a list, with the closest at the top.
  • User can scroll through the list and get a summary (size, distance, type) on each of the caches.
  • Selecting a cache moves to the display screen for that cache.
  • List can be refreshed with a “Refresh” command.
  • App can be exited with “Exit” command.

Display Screen:

  • Queries for and shows all details (description,etc) for a particular cache.
  • Commands are “Back” to move to Location Screen and “Track” to move to tracking mode.

Tracking Screen:

  • Application will display the name/ID of the selected cache, and distance to it. The GPS will be queried and this information updated continuously.
  • App will also display a “hotter/colder” designation based on whether the distance is increasing or decreasing.
  • Hotter/colder may also have an audio cue — an ascending tone for hotter, descending for colder. (The absolute pitch might rise as you get closer, too.)
  • “Found it” command will shut off audio notification and allow logging the find on
  • “Back” command will bring user back to location mode.
  • “Hints” command will retrieve hints from and display them.