Instagram Image downloader allows you to save or download media from instagram. Using this you can save any videos images or igtv contents for free. This is currently a free tools and open to all and in future also it is going to be the same.
Yes, it's legal to download your own contents but it's not legal if you download other's content without their permission or consent. If you download other's picture or videos and use somewhere else you might need to face legal consequences.