Existing Android quiz app-Maintenance and enhancements

I have an existing free Android app that has been published on the Play store for 3 months. I need a programmer that can both make some enhancements (within the next 30 days) and be in the position to help with any maintenance in the future. Enhancements include: -Adding a leaderboard to show rankings. (I will provide the design, images and layout.) -Implementing a registration and login ability. The current app requires logging in with your Facebook credentials but I want to allow logging in using your registered credentials. Current maintenance issues include: Facebook profile images sometimes do not show. Possibly a memory or caching issue? The current app consists of about 60 [login to view URL] files. The primary database for storing user data and game play is on a server. The app makes calls to a PHP api that I wrote and maintain. I am a programmer and can make tweaks via Eclipse but I am not an expert Android programmer. I will also publish the app at the store. Most communications can be via either email or Freelancer messages or Skype. I always provide very detailed specifications along with screen shots. If I hire you, I will expect documentation on changes you make. The documentation does not need to be detailed but I will want some description of what you did. Or even better is documentation within the source project with a time stamp. I am only looking for someone that has a lot of Android experience and can help me on a timely basis. I will usually be able to give you one to two weeks to perform a task but I cannot afford for it to take longer. Initially the project could be on an hourly basis but once you become familiar with the code, I would be open to a fixed price per task. The original programmer worked on this for 9 months doing part time. What I need now is someone that can implement changes within a week or two and NOT months. I also have the same app published on the iTunes store as an iPhone app. Even though this Freelancer project is for Android, I need to make the same changes to the iOS app. If you could do iOS also for less than my current programmer, I would consider it. Please bid your hourly rate and reply by describing your experience and how you can meet my needs.