If you want transfer apps from D2 to the D3, you can do it withs Android Backup Manager export/import feature.
Actually you can transfer contacts files from D2 to D3 directly.
- Connect two Devices to PC.
- Choose the category list of one device that you need to export files.
- Check the files that need to export in the Content Panel and click "Transfer Apps from device to device" button.
- All the checked files from one device can be transferred to the other one.