Write an AndroidTABLET ANDROID APP connected with JOOMLA VIRTUEMART ESHOP application

Hello Freelancers I have an eshop that is a Joomla 2.5.X with Virtuemart 2.0.X I need a custom application to run on a android tablet so a salesperson can use it This application will RETRIEVE (whenever we like, for example we inserted new products, we adjuste prices) all the data from the online eshop to the tablet. Imagine that a salesperson holding this tablet visits a customer (this app can work without internet connection) This application MUST HAVE the following features: CONNECTION/DATA - Connect (when there is internet) and retrieve all items (categories/subcats/items/prices) INTERFACE - Large Buttons - Nice Minimal Design - Not Fancy Things - Just Productive and easy to use - Language is UTF8 and can provide all translation needed CLIENTS TABLE/DATA - Insert/Edit/Delete client data (for example Name, Surname, Address, tel...) - Have the clients list alphabetically so we can easily select to see historic orders - Ability to send by email the client data (specific one or all) - Can browse previous stored orders from each client (items/total price) - Can see a total money of all all previous orders by client ITEMS/DATA - Browse store categories, subcategories, items from the eshop - Ability to search an item by SKU or ITEM TITLE (has the SKU code there also) - Select items and insert (with quantity calculated) to a cart - Ability for custom text field for notes to write in the order - Ability for custom extra discount for total order - Ability to save the total cart (for historic view of the client) - Ability to send by email the total cart (to selected customer or bcc to others) NOT NEEDED FUNCTIONS - We dont want to send items from app to the eshop - We dont want to add/insert clients from app to the eshop (just email as described) - We dont want to add/insert orders from app to the eshop (just email as described) WHITELABEL - I want this application to show my eshop/custom name design and not other company because I have already some offers and I dont want to spoil any good relationships (I guess you understand me) FINAL CONCLUSION I dont know if I have forgotten anything but think of having an store and your salesperson that will visit other customers must have a tool with him that can do any possible actions of storing an order and deliver them even later when internet is not available FOR ABOVE I NEED EITHER A CUSTOM MADE SOLUTION OR A READY OUT OF THE BOX APP THAT YOU CAN MODIFY AND DELIVER PS : I am looking for a reliable solution since there is a more than 50 eshops client-list-waiting for a mobile/tablet application solution even as salesperson driven or client-app-used (like common apps) so we cooperate in future productions.