If you have seen something on YouTube that's worth downloading, but you don't know how to do it, you are in the right place. There are tons of third-party programs that can provide download services for YouTube. Tuber might not be popular enough, but it will download your clips in a jiffy.
The UI is built as a standalone YouTube client, meaning that you can explore and search videos directly from inside the app. Also, depending on the country you live in, the Trending page will be populated with videos specific to your location. Sadly, it appears that there is no way to set up the app to generate content from a different country.
Searching for videos is done exactly as on the website — use the search function and select the video to open it. Under the search bar, you can also find two display-related buttons, which influence the position of the thumbnails.
The download and conversion are both executed from the same windows. To be more specific, after you've searched for a video and access it, under the actual content tab, you can find a list with the available formats for download. The application should be able to download up to 4K in quality, but that doesn't mean you can download everything in 4k, but only if the video is available for that quality/format.
Also, make sure you determine the download locations, as the app has different paths for video and audio files. To be more specific, every time you download a video, pay attention to the format, because the audio (MP3, WAV) is saved to another location.