Here's an overview of the best dating sites on the market. Bumble requires women to message first and if the guy doesn't message back within 24 hours, he loses the potential match.
My recommendations for the best dating sites are based primarily on my own experiences with online dating sites as a woman, with some word-of-mouth impressions from friends thrown in for good measure. Because that's the one thing my love life was really missing... The timer is designed to encourage contact, and some people really do appreciate that feature.
It's a cool concept and helpful for people who want to meet someone in a more organic manner.
That said, I've never met a single person who actually uses the app.
The downside is that short profiles make it harder to figure out what people are looking for.