or... maybe this is just a fun side project they whipped up as a joke? Some side project for a resume?
Just look at OP's comment history, one example:
> I absolutely love making chrome extensions - my very first one was creating an extension for tinder.com that would swipe left on anyone with the first name Chad
All they require here is your name and email, and the recipient's name and address. Both are (probably) public somewhere and in combination are almost certainly still worthless (or certainly worth less than the postage they're giving to you for free)
Just look at OP's comment history, one example:
> I absolutely love making chrome extensions - my very first one was creating an extension for tinder.com that would swipe left on anyone with the first name Chad
All they require here is your name and email, and the recipient's name and address. Both are (probably) public somewhere and in combination are almost certainly still worthless (or certainly worth less than the postage they're giving to you for free)