The app now stores the video received through the LB in a "cache" on the phone/tablet whenever the camera is recording, so you'll always have a "preview quality" copy of what you're recording on your device (shows up in user center->album). These cached clips apparently need a "conversion" step before you can play them or use them in Director, but you obviously don't need any connection to the craft to use them.
You can then select parts of any clips you have to create "moments", then just put those "moments" one after the other, reorder them and fine trim them, and export. It automatically puts some music (that of the one of 4 "templates" you've chosen) and an "inspire 1" credit with your pilot name. Once that's done you can review the result/upload to youtube but not modify it anymore, you'd have to start over.
No color correction or anything. It's really meant for the type of people who tend to love instagram and want to share their "awesome" creation right now without spending more than a couple of minutes on it and with no emphasis on quality. Very trendy nowadays with the general public, and also spot on for pros with current marketing techniques ("wow see what I just shot 5 minutes ago!" to build up excitement until you come up with the proper edit a couple of days later). It's actually quite well done for the purpose.
Should work for what you want and can all be done on the phone. But then again, if you count the conversion/export times I'm pretty sure you can whip out your powerful laptop, shove the Inspire's SD card in, throw the files into your favorite NLE and do the same trimming in about the same time but in full quality and being able to reuse that as a basis to continue your editing work later instead of having to redo it from scratch.