Video editing

Hey guys,
I have started a channel called “Easy Yoyoing” and I had a question. This is especially to people who have seen most of Brandon Vu’s videos. If you have noticed, which you must have, he inserts small photo and video windows into his videos. He even gives it a nice effect, he points at the place where he wants them to pop up and sets the timing so that they pop at that place at the perfect time. I want to know if there is a software which allows me to do that but it has to be free. My parents won’t be paying for a software. I asked Brandon Vu what he uses over Facebook but he uses a paid software. Please do tell me if you know of any software and be sure to check my channel out!
Thank you!!

Also, it’ll be great if the app is for iPhone. Thanks again!

If you run ubuntu on your computer you can download Open shot video editor which is a pretty good and free editor.