Starting from iOS 10 release, Scanner Pro allows the users to take and attach scans directly in Messages app.
Try the new extension following the steps below:
3. Start scanning the same way you got used to it in Scanner Pro.
4. Edit the scan (change the name, pick the file format, edit the scan using all Scanner Pro features or add more pages).
Once you are done, tap the blue checkmark, attach the scan to the message and send.
Note: Naming scans in PDF doesn't work due to the current iOS 10 restrictions.