When you hit the save button the Mission Plan is saved and can be seen in the Mission Management screen. From there, you can send it to other users if they are using Map Pilot Business via AirDrop or Email.
https://support.dronesmadeeasy.com/hc/en-us/articles/360001149163-Sharing-Missions-Between-Devices
This utilizes the .mme file format.
If you turn on Mission Sync in the Maps Made Easy section of the Map Pilot settings you are able to sync all of the missions on the device up to Maps Made Easy. From there they are viewable at https://www.mapsmadeeasy.com/map_pilot/mission_plans/ or can be synced onto any other device that is logged in using the same Maps Made Easy account.
Maps Made Easy serves as the central repository for your missions in case something happens to your device.