Need help with possible stolen sensitive information

So a month ago, my family needed to get their pr card renewal and so we needed to compress some files. A problem with this is that Adobe couldn't do it so I instead used a free online compressor. I knew that some could potentially have malware so I searched through reddit and found this one https://www.reddit.com/r/SideProject/comments/1qus0rq/made_a_free_pdf_compressor_that_works_in_the/

. The person who made it said that it would be completely client only with no servers but a comment said that it was sent to the server. This made me completely freak out since it had personal information since it was an noa and t4 so it had stuff like our address, sin number, and legal name for my mom (I'm a teen so I tried to do it for her). So hearing that it could go to the server made me hyperventilate since I have ocd and they will have a lot of information about my mom. I looked at the guy's (or girls) history and found out that he's from India and I mean ABSOLUTELY NO OFFENSE to anyone but india does have more scammers than usual (please don't take offense) and his history said some stuff about hacking? Idk there might be nothing wrong but just saying. So what I'm now wondering is that is it really not client only? Is the server really involved? Does he have my pdf/info? Is there anything I can do to prevent or stop something? Please help. I'm panicking a lot right now.