Building Android Application that connects with SAP

I am building an Android application that connects to SAP backend/ or SAP Web service. Some points worth mentioning are:

1. A similar web application is working, which connects to the same SAP web service that I intend to connect. The application takes two - three inputs from user and saves data into SAP database, and returns success/error message along with tabular data.

2. I tried an application using Sencha Touch that connects to SAP demo server, but the demo system has been upgraded and the application does not work on my system.

3. In case it matters, my comfort level in SAP is intermediate to expert, intermediate in Web(HTML5/CSS3) and that in Android is beginner to intermediate.

Any pointers would be welcome.

Regards Dinesh Dhiman