Surfwords doesn't collect any personal data. Actually, right now it doesn't collect any data at all. If I change my mind about data collection, I'll let you know and give you the chance to opt out.
Maybe Google and Apple do as a result of using Surfwords, but that's between you and them.
If you opt to use Google and/or Apple's leaderboards, Surfwords will send them your scores. What they do with those scores is between you and them.