There are a lot of editing apps available now: Splice, Imovie, ReelDirector, etc. But after multiple google searches and a lot of sniffing around, I still can't find this…

Is there a video editing app that will let you execute J-cuts and L-cuts. In other words, cut the picture from shot 1 to shot 2 but keep the audio from shot 1going, or cut the audio to shot 2 but keep the video from shot 1 going.

It's impossible to properly cut a narrative dialog scene without this, but I can't find an editing app that does it.