Thanks to Steve Davelaar the A-Team has launched a new (open source) JDev/MAF 12.1.3 extension called APAM (A-Team Mobile Persistence Accelerator) to achieve working with an App in offline mode - and lateron sync with the host (data); in the A-team blog it is described as follows:
AMPA is a lightweight persistence and data synchronization framework that works on top of Oracle Mobile Application Framework (MAF). It eases the consumption of RESTful services, and provides a complete persistence layer that allows you to use the mobile application in offline mode. You can read and write data while not connected to the internet, and synchronize any pending data changes later when you are online again. The design-time wizards that are integrated with JDeveloper enable you to build a fully functional mobile application within minutes.
Furthermore AMPA includes an easy way to make use of RESTful/JSON services utilising a declarative wizard.
For more pls consult the A-team blog.
The sources are available at GITHub as being an open source framework.
Go to the AMPA GitHub Home Page and click on the Download ZIP button to download the source code to your computer.
Sorry for cross posting - but you might not have heard about this.