Pool Plus Friends is a turn-by-turn game of pool for Windows Phones that’s free and available now. Here’s the description:
Pool Plus Friends is a fun and exciting turn-based Multi-Player pool game. Challenge your friends to a casual game of pool or just practice in single-player mode against built-in robots.
Pool Plus Friends can utilize push notifications and network capabilities of your phone to connect with other players online.
• Push Notification Support
• Single Player Mode
• Multi Player Mode
• Friend Portfolio
• Easy-to-use aiming controls
• High Scores
It has very positive reviews so you may as well give it a shot (no pun intended).