Unity3D Plugin for An Android AD SDK

I need to get a Unity3D plugin created for an Advertising SDK for Android. Unity plugin must expose all features to games for integration which are provided by original Android SDK. I have detailed documentation, native ad library and demo, which I will be sharing with selected developer. As a developer, you will need to provide me a Unity Plugin package which C# bindings for the ad library and enable me to trigger methods of their Ad SDK with in my unity3d game. As deliverable I will need complete source of the plugin, documentation & a sample project in Unity3D showing plugin functionality. All deliverable will belong to me and my company only. *Important* I don't want to waste time, therefore bid only if you have created Unity3D plugin for Android and know how to use proper name spacing to avoid any conflict with other plugin. You will need to share reference of those plugins which you have created. As our games are using many other plugins, at any cost we won't be able to accept plugin which breaks or cause conflict with other plugins. If you need to know list of those plugin in advance, please do let me know in your proposal. Please note that this project is about creating plugin of Unity3D (unitypackage) and routes like export unity project to eclipse and integrate their SDK in eclipse project won't work. We need this job to be done with in 4 days period. We will pay in full only after getting plugin sample. Then we can pay 50% and you need to delivery source code for plugin and we will then release remaining. No upfront please.