You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature currently requires accessing the site using the built-in Safari browser.
This issue has been discussed in other threads. You need to raise the speaker volume to maximum while placing and receiving a call to hear the other person. The holiday update caused this issue. Hopefully it will be corrected in a future software update.