It's OK. The concept probably is more attractive to men than women, with it being the women that message first. But, it also reduces the number of people you interact with. 9/10 times, you won't get a reply to the initial message before the 24-hour countdown is over and also a good chance you won't get a reply after that. I don't believe in paying for dating apps, as I don't think it's worth spending money not to find what you are looking for, and this is no different.