Thanks for reading! My friend and I have not decided yet if we want to sell the code. If we want to do it, it needs to be refactored first. Unfortunately, it's not guaranteed that the app works every time because you have to update the scraper when TikTok updates its website.
If it comes down to content scraping in legal terms, it's always a grey area. In this case, the TikTok app provides a download button that enables you to download the videos to your mobile device. This would be equal to downloading the videos from their website. I don't encourage content scraping if you don't know what you are doing, you should always know the risks before starting a project like this.