Develop a webapp from a website

I have a website built up and need a webapp for the same due to budget constraints. We have already worked on the web app and found some issues like: 1. when we rotate screen to landscape to potrait view, it jumps to home page of the web app. 2. when we submit a form and click back, it shows some error message. 3. when we see app in landscape view, the loading image gets squeezed too much We prefer to rectify the issues. Or you can create it from scratch. But we need the work to be done really [login to view URL] to rozgaarwindow[dot]com which needs to be converted to web app. Original codes and adequate live information should be given about the codes done.