The only other app that I’ve seen used in several places is GroupMe, but that’s typically reserved for large groups (more than 10 people or so) that may include people you’re not friends with, but more acquaintances. So it’s been used for school classes, community groups, and things like that.
Me and my friends don’t care about green vs blue bubbles or any of that garbage. We just want to be able to communicate over the paid cellular plan that we already have. What happens in Europe has no bearing on this. All I pointed out by my comment above is that this is a problem and there are people that would like a solution.
And, not that this matters, I’m writing this on my iPhone. But, this is still an annoying problem to me because much of my family and some of my friends use android. Apple degrades my experience with family and friends for no technical reason. The only reason they do this, presumably, is to retain a large market share and promote some stupid “exclusivity” ideal that appeals to some people.