Is there a voice recognition app that, allows me to interact with various web apps and modify certain actions and link them to command word?
Jott is a service that provides you a telephone number you call to control various web applications by voice. It has built-in integration with many different web applications, including at least Remember the Milk, Google Calendar, Twitter, Facebook, Blogger, and WordPress. The last time I checked, they let you add additional services pretty easily via a simple web-based API, which was pretty easy to use. I have no idea whether that particular piece of functionality still exists, but if it did, it might provide you the full functionality you're aiming for.