I can't find literally anything about this service anywhere else on the internet. Almost all results for it point back to this subreddit to boot. I've never heard of this VPN before this subreddit, and it doesn't even look like one that VPN subreddits have ever talked about before.

On top of this, it's free - you should always be cautious when anything is free, because often times it means either you're the product, or they have an ulterior motive. There's a reason most VPNs cost a subscription fee - they have to be able to pay for servers while also making sure your connection is safe and private. You aren't getting that guarantee with a free product, not to mention one with very little history (and the fact that it's the only app that company has produced).

"Free" VPNs have plagued the Play store for years, siphoning people's data and/or selling their information to third parties and not protecting them well enough.

Maybe Surf VPN is legit, but the fact that you can't find almost anything on them, and the fact that they're free, is definitely enough reason to be sus.

Stay vigilant.