Here is how you export:
1) Tap on "More..." in the bottom right of the main screen of the app
2) Tap "Advanced Features" on the first line of the next screen
3) Tap "Import/Export" on the next screen
4) Tap "Export" on the next screen
You will then see a message that says "Export Complete"
5) Tap "Share" right below where it says Export Complete
6) You will then be presented with several options for sharing. I think the easiest way is by email. I just choose the name of the email program I use (Gmail) which is listed on the second line.
7) Fill in your email address to send the file to yourself
8) Send the email
9) Open the email on your second device
10) Click the attachment and it will automatically import to the DCS app on that device. The MTH app does not have to be open to do this.