Android

What application should I use for reading Barcode and QR-codes?

Use the Barcode Scanner application from ZXing Team. On the Getac Z710, a barcode scanning app might be already installed, if the device has a dedicated barcode scanning module.

What application should I use for editing picture documents?

Use an application fitting all requirements is Photo Editor by Aviary.

What application should I use for viewing and editing PDF documents?

Use Adobe Reader from Adobe.