The problem with this free app and other free or very low-cost data broker opt-out apps is that basically how they work is they send an email to every data broker on their list with your data asking them to delete it.
What ends up happening is that if a data broker on their list doesn’t have your data already, well then… now they’ve just received your data in the opt-out request. Obviously they’re not supposed to do anything with that data, but they’re data brokers, of course they’re going to keep it.
So basically if your situation is already really bad and you’re showing up in databases all over the place, then it’s probably good to use to immediately tackle all the biggest offenders at once. If not though, you might end up giving out your data unnecessarily and potentially making things worse.
This is why programs that scan the internet for your data and then send an opt-out request when they find something are better. Unfortunately it tends to be more expensive to do so.