I feel like this page may be a little outdated, as I don't have time to keep all the apps up-to-date, and a lot of them were written back when there was only one phone size, and are no longer following modern mobile web standards. Still, it gives me something to keep working toward. Here are a few that I've worked on, in alphabetical order.
A weather app that gives you the current conditions, radar map, a five-day forecast, defaults to your GPS coordinates, but has preferences that can be changed. Note: This is the old version, a standalone domain version has been created at http://accudan.dangoodspeed.com/.
While it's pretty easy to figure out when certain yearly anniversaries come by, but what if you want to get a little creative and measure in seconds, minutes, hours, days, or weeks? This picks out a few of the more significant anniversaries there given the original date (and time if necessary).
Are We There Yet?
Demo/proof of concept app. There are apps that tell you your progress toward a destination on roads, but what if you're going someplace that doesn't have an address? This app is especially handy if you're hiking on a new trail and want to know how you're doing. It uses your phone's GPS to tell you how far you've gone (in miles, ninutes, and percentage), and extrapolates to guess how far you have to go (in miles, minutes, and percentage), as well as giving you an approximate arrival time. The demo version requires you to know your destinations longitude/latitude (or use one of the demo saved locations).
Maria's Capo App
Ever look at the guitar chords for a song and think it would be easier to play in a different key? This app lets you put in all the chords, and tells you what chord shapes you'd need to play in the different capo positions to perhaps find something easier.
A simple interface for access to short sound bytes up to 15 seconds long. In this demo, I just use sample short introductions for performers at my open mic.
Where Am I?
A simple app that just tries to figure out where you are, give you the GPS coordinates, and the best guess of a street address of your location. Convenient for telling a friend where to meet you when you're not sure of the address.
An SQLite-based anagram app to make words out of given letters, using the words database from Words with Friends.