One is a big proprietary blob of mistrust and the other is localtunnel? Sorry if that sounds harsh but it's a shame I can't build and make sure that everything is above board.
Good on you though , that apart it seems a great idea well implemented. Easy to throw stuff up for prospects/clients in an agile way without having to talk to devops.
Why not free as in bird? It is already free as in beer.
I stopped used ngrok because after opening the tunneled URL a few times it started saying "too many HTTP requests" on a Wordpress project. It is common for those to have many images/scripts/styles so throttling by number of requests makes ngrok unusable, now a happy localtunnel user.
ngrok has connection limits, but not request limits. Perhaps your server wasn't using keep-alive connections? It's mentioned in the pricing FAQ (scroll down a bit from this link):
Yeah my bad, it probably says "connections limit", I don't have time to figure out my way around it; other devs may do thought. I just want to fire it up and start working.
Not really, it was just an example; you can leave blank the Wordpress theme index.php and that way it makes only that request; the problem is more general: Real web sites are full of content (AKA. full of requests), that's just how it is.