With the osFinancials or TurboCASH Adaptor and ordering App you can download your clients and stockitems (images if you have multimedia).
You can then connect the app the the local server that osFinancials can run to collect your data into your Android machine. You don't need internet to show your items and make orders.

After making orders you can upload the orders when you get home to osFinancials or TurboCASH.

You client can even sign the order and you can email the order with the signed image.
For 25 (exl tax) Euro per year you can use the adaptor the App is completely free.

Read the manual for the Android app here
http://www.osf-boekhoudpakket-administratie.nl/index.php/en/plugin-manuals/541-android-app-en

And the manual for the plugin in here
http://www.osf-boekhoudpakket-administratie.nl/index.php/en/plugin-manuals/542-android-adaptor-en