I don’t have a lot of experience on the Mac side, so there may be better suggestions there. I’ve used Windows Movie Maker on the PC side, and it’s pretty simple (and the price is right). It’s no longer available from Microsoft, but available at other sites around the interwebs.
No idea how complex it is (a friend uses it and I wouldn’t describe him as super technical), but you can grab Pinnacle Studio 24 Ultimate for a lowly US$1.37 on a current Humble Bundle.
^-- free and should suffice if trimming or slapping together some videos is all you need to do. For some more fancy stuff, other software will probably be suited better.
Is there some logic about which way an iPhone records video when viewing on a PC? I don’t think i’ve actually managed to record a video on the iPhone that is viewable on PC the right side up even once. I’m probably just going to buy a camera for work purposes just to stop having to edit every video I take.
It’s even more annoying because when you view it on an Apple product the video is right-side up, so it’s hard to cross pollinate here. It’s not a big deal for personal use, but i don’t have time to mess with this on a work level.