It's billing itself as “Tinder Minus Marriage-Minded Daters,” and it's available on both i OS and Android.
Now, not everybody does that of course, some girls like to play, and sometimes lose themselves in the game, or hurt people. A Frenchwoman is expected to play her feminine side, and be “admired” for her beauty and wit among other qualities.
Frenchmen like to flirt as well, even if they know very well there is no hope of it leading anywhere.
But I would never do that to my Dad who would be very upset if I did. When I meet a man and I am without my husband, I’ll place within the first minutes of the conversation that “my husband blablabla… That usually is enough to make my state of mind really clear.
I did the same thing as a girl, talking about my boyfriend (actually existing or not) early on in the conversation. And some people are just not faithful, but contrary to popular opinion, it’s not worse in France than anywhere else (and several studies demonstrate it). It’s in our genes and it’s socially accepted in France.
Casual X obviously caters to a pretty specific segment of users.