That very elegantly sidesteps the question: is this app uploaded by you or by the original author or by someone else entirely?
This is common on mobile app stores too: for example there are many variations of the ZXing barcode app which all follow the terms of the open source license, some are even paid apps.
Another example would be cloud services offering commercial products based on mysql, redis, elastic...
As a community, do we want to be sending eyeballs to the original source, or a monetized copy?
OP is free to do what he or she is doing, we are free to block it as spam or link to the original source.
I can see why this would get some people fired up. It definitely feels a little gross presented in this manner. But... it IS MIT liscense. Nobody made the author release it this way.
He could have easily released the demo on his own website and not provided the code "without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies".
I'm glad people pointed out the original author, I just went and browsed his codepen page. But we have to assume he is OK with people coyping or even selling the code assuming the license is not breached.
I'm saying that links to this kind of aggregator have no place on Hacker News. What benefit is it to the community to have the authorship hidden and ads added?
Talking about licensing is orthogonal to my point. Blogspam is totally legal and not accepted here. This is no different.
Not the first spam, one of which was even titled Show HN: