This is a community wiki, to collect a list of contest sites that offer winning prizes for Android applications.
This can be anything where Android is accepted, or where OS platform and GSM providers are not specified so I can apply with an Android app. It should also NOT be region specific, so someone from EU or Bangladesh can apply.
Thanks for the question, because I didn't even think to look around until I saw it, and now I'm interested!
Google is running an Android Developer Challenge and the full eligibility details were just released. There are some restrictions regarding country, but Bangladesh isn't one of them. The terms are found here.
World’s best app? Let the 2011 competition begin! http://mobileappsshowdown.com/2010/08/11/best-app-in-the-world-let-the-2011-competition-begin/
Game developers everywhere are invited to create and submit their original titles for the iPhone, iPad, or Android platforms from July 1st through October 31st, 2010.
The Grand Prize winner will receive a $25,000 cash prize and the option for a publishing deal with the possibility of developing the mobile game for other handheld devices and video game consoles. Our panel of industry experts and indie developers will determine the winner. The Community Favorite is determined by votes from the indiePub community, starting on September 1st. The winner will receive a $1,000 cash prize. There are four Public Recognition Winners: one each for Technical Excellence, Art, Audio, and Design. These winners will each win a $1,000 prize.