Awesome, very well done! I'd consider reworking a couple of your comparison table headings, maybe something like this:

"iPhone only" -> "Supports all smartphones"

"Participants need the app?" -> "Participate without [installing / the app]"

"Max participants" -> "Unlimited Participants"

This purely subjective on my part, simple because I think it's easier to read a list of "YES" answers, and compare against the competitors's "NO" answers :-)