In another effort to help it combat Apple's wildly popular App Store, Google showed off the winners of its second Android Developer Challenge.

The contest includes a variety of judges from places like Google, T-Mobile, MTV, and Twitter, and it names the best Android mobile applications across various categories like education, entertainment, games, media, and productivity. The overall winner received $250,000, while the winner in each category received up to $100,000.

The overall winner was an app called "SweetDreams," which will send late-night phone calls directly to voice mail depending on what the user specifies. An app called "What the Doodle!?" nabbed second place by offering Android users a real-time online multiplayer drawing game. The "WaveSecure" app took third place and it enables users to back up data, wipe data remotely, or lock down a phone remotely if it's lost or stolen.

The cash prizes will likely be well-received as there are growing reports that many developers are having trouble making significant profits with Android apps. A recent survey by Skyhook found 57% of developers were unhappy with their Android app profits.

Some developers have complained that with the growing number of Android devices with different screen sizes and input methods, it is becoming difficult to optimize programs. Additionally, developers have complained about Android users' relatively low download rates, as well as the requirement to use Google Checkout for buying programs.

By comparison, Apple's app platform is relatively more streamlined because there are only three iPhones in the lineup, and many users already have credit cards tied into the iTunes ecosystem. But the App Store is not without its faults either, as Apple acts as a strict gatekeeper and some developers say its approval process can be arbitrary or unfair.