Edward Yau found himself in a common predicament. It was time to choose a school for his 4-year-old son, but finding a top-quality preschool is a notoriously herculean task for any parent in the city of New York.

There is myriad information available online -- ranging from state testing scores to public school report cards -- but "the information is really scattered," Yau says. He spent hours combing through data and placing it into spreadsheets. With around 2,000 private and public preschools to sift through, it was an exhausting process.

As a software developer, Yau saw opportunity in his frustration -- so he built Sage, a free app that amalgamates school stats from across the Web into a single, easily searchable form. The app allows parents to search by address, intersection, ZIP code or school name, and results display each school's basic information, state exam results, NYC progress report grades and admissions tips. "I built it because I needed it," says Yau. "There was no alternative that had up-to-date school data."

City life has always had its challenges -- schools, transportation, neighborhood conditions -- but now across the country citizen-developers like Yau are coming up with mobile-friendly solutions by tapping into a wealth of disparate municipal data, from restaurant health violations to noise complaints.

Where the average citizen might be overwhelmed sifting through massive digital warehouses and spreadsheets of minute municipal data, these coders are finding inspiration for such useful city apps as these:

Wondering when the next bus comes? In Portland, Ore., PDX Bus, a free, open-source iPhone app, delivers bus and train arrival times by tapping transit data, including GPSes built into city buses.

Need a parking space but not a parking ticket? In Baltimore, Spot Agent parses citation records meter by meter to show users where an expired meter is most likely to yield a ticket and, conversely, where enforcement officers tend to tread lightly.

Committed to greening up your neighborhood? In New York, 596 Acres, created by a Brooklyn-based non-profit, gives would-be urban gardeners contact information for agencies that will grant them access to vacant lots. It also keeps tracks of projects started through the app, allowing like-minded green-thumbed Brooklynites to connect on a garden.

The PDX Bus app uses city data from Portland, Ore., to show estimated bus arrival times at specific intersections. New York and Boston are among many other cities where citizens have developed apps for public transportation.

Data deluge

This rapid emergence of municipal apps is being fueled by the release of a deluge of municipal data.

Over the past decade, much information that was once paper-based has made its way online to various government websites and databases. That movement drastically accelerated in 2008 with the Obama administration's Open Government Initiative, which led to the digital release of vast amounts of federal data, with many sets now available in a publicly accessible database, Data.gov.

Multiple municipalities followed suit, often following the Open Data Policy, and have now significantly upped their online data stores, releasing hundreds of data sets free of charge -- a first for some agencies.

Those efforts have been praised by open government advocates, particularly policy wonks and journalists who have long sought out public data for everything from legislative campaigns to behind-the-scenes exposés. "Those municipalities that have made strides in making data sets available are moving in the right direction, and that's worth applauding," says Kenneth Bunting, director of The National Freedom of Information Coalition, a nonpartisan alliance of organizations dedicated to information freedom.