For all of the videos I put together on my YouTube channel, I use the paid version of Wondershare Filmora (available for both Mac and PC). Although, if you don't want to buy the program outright, there is a free trial version, but any video you export will have a giant watermark on it. That said, I would recommend getting the free trial (this version is exactly the same as the paid except with the watermark) to test it to see if it fits your needs before you purchase it.
For the iPad, iMovie is pretty much the best way to go, but I typically never edit on there because I can get better results on my Mac or PC (I do have both).