Chromecast is cheap and small, making it perfect for a projector. If you have a iOS device, you can't mirror to it. This Instructable will show you how to do that.
Step 1: Set Up Computer
Your laptop will act as a server for pushing AirPlay to Chromecast. Download the app Mirroring360 mirroring360.com and download the Chomecast extension (requires Google Chrome) from the Chrome Web Store. Once you open the downloaded file for Mirroring360, open it and drag Mirroring360 to the Applications folder.
Step 2: Set Up Mirroring
Start mirroring your laptop to Chromecast. To do this, click the Chromecast extension in Chrome, click the arrow in the top right corner, click cast entire screen, and click your Chromecast. You should now see your laptop screen on Chromecast. Launch Mirroring360 and set it up.
Step 3: Mirror to Chromecast
To start mirroring to Chromecast open Control Center on your iOS device, tap AirPlay, tap the name of your laptop, and turn the mirroring switch to on. You should then see your iOS device's screen on your Chromecast. Press the full screen button on your laptop and enjoy.