SayHi says it is free but in reality it is not really.
It cost nothing to join and chat with common users and users who pay which are called VIP. You end up needing to BUY points though to chat with popular users. I use Android as well but at least iTunes list prices for what costs money on SayHi. To say the least it is not cheap especially if you want to be a VIP. Here are the prices:
150 points$3.99
500 + 50 points $9.99
1000 + 200 points $19.99
Messaging monthly plans (1 month) $20.99
VIP for 30 days $89.99
5000 + 1600 points $99.99
Super VIP for 30 days $139.99
8500 + 3500 points $139.99
Messaging monthly plans (3 months) $54.99
You can earn free points if you want but it takes a lot of work and IMO not worth it. I would recommend trying another dating service.