They had matches, and you could still message. I don't imagine the app version was much different than the web version in that respect and I used the latter.

It's really not hard to look up. See here: https://help.okcupid.com/article/40-how-to-send-an-introduct...

The only thing that's changed since I used it is they want you to hit "like" on their profile before you send a message. That's not an impediment. The option to send messages is not gone. Use it.