Here are some plugins for Unity that I have written and use myself. From time to time I will be adding more plugins so please subscribe or follow me on twitter.
All the plugins come with a ‘if it doesn’t work as you expected, you get your money back’ guarantee. If you are not completely happy with the plugin, let me know and I will refund your money.
The Unity3d plugins available include Admob and Mobclix ad banner integration, in-app purchasing and coming soon, a social plugin adding facebook integration.
There are some simple tutorial videos on my youtube channel now, so please check them out!