Yes Clipchamp is an excellent video compression app. We convert your video into an MP4, WMV or WebM container and in most cases, the resulting output video will be (substantially) smaller than the input video.
The exact quality and size of the output video will depend on the input video and the output settings you choose. You'll see all available output options after you've selected an input video.
If you're not sure what to choose, it's best to give it a try with our standard settings and see if you're happy with the result. If not, try a different output setting - the larger the file size you choose, the better the quality of the converted video will be.
Please note that some conversions might not result in a smaller output file due to the type of input file (for instance its original resolution, video and audio codec) and a number of other factors.