Android application needs bug fixing and update

I have an Android app that needs bug fixing. The Android app contains a number of bugs related to (the optimization of) the different screen sizes, resolutions and dpi of Android devices. It is missing some minor functionalities and it also contains some bugs that makes the app crash. I am looking for somebody with experience in Android mobile device programming and can deliver a quality piece of work in a short time frame. I will be looking for solid credentials and a very cost-effective freelancer. Please respond with level of ability in App development, samples of work and price quote and I will send details to the person that best fits the project. There will be 2 weeks to finish the project. Budget around $250 - $500 Skills required: App Design and Development, Mobile App Testing, Android, Mobile Phone, Programming, Java. Please note that a Non-Disclosure Agreement will be required to sign in order for me to discuss the project in full.