I don't want to touch it if it had ads. Hacker News is a community I like because its users generally promote the "Hacker Ethic" [1]. As far as I can tell this app has no infrastructure costs because it just uses the HN API. In putting ads on it, the app author is monetizing a free service they like to use. That is the opposite of the Hacker Ethic.
[1] https://en.m.wikipedia.org/wiki/Hacker_ethic