Once synced, the data is stored on the device in a partition reserved for our application.
On iOS, this is encrypted using the same techniques as Apple encrypt email. The security is only as strong as the password set for the device. This is default to four numbers (10,000 possibilities) which is not very strong. We recommend our customers enforce a policy where users must implement a “Settings > General > Passcode > Simple Passcode = Off” and use a passcode of at least 8 characters/numbers.
On Android devices, we recommend enabling Android's Full Disk Encryption (available since Android 3.0)
Unplugged also has the capability to set its own 4 digit pin code that you may configure within the Settings option on the specific platform.