*Edit, just saw tat other people already replied, sorry for doubling on information
Hi Macius,
The way the Mavic (and probably all other DJI drones) work is that they store the recorded data (photo's videos) on the SD card aboard the drone.
However, they also stream the video signal from the camera to your device via the remote connection. You can imagine that the stability of that stream is highly dependent on the strength/robustness of that remote connection. Whenever the signal becomes weak, the priority is given to control inputs, rather than the video signal. Now, the app enables you to store the video stream from the remote connection in the cache of your device, and then you can "download" (basically move it to the photo roll or photo app) that.
Now, the quality of that stream is already lower than the one stored on the SD card aboard the drone. On top of that, it may contain hickups due to bad connections.
Do you want to buy a $1000,- drone, yet save a few bucks on an SD card?
So far for the unrequested good advice. To answer your questions more bluntly:
You can store the data on the ipad (after filming, go to the editor and click on the download icon), but the quality will suffer hugely, and it does require manual clicking.