Handle a call without touching your phone's screen with the Gestures Beta app for Windows Phone
If you place the phone flat on a table with the speaker-side up, the speakerphone goes into operation. Best to make sure that you remember which gesture turns the speaker on and which one mutes your phone. If you forget which does which, you could make a mistake fatal to your career! Note that those sporting the Nokia Lumia 630, Nokia Lumia 635and Nokia Lumia 530 will have limited functionality with the app.
The Gestures Beta app is a free download from the Windows Phone Store, and allows you to answer the phone, enable the speaker or the mute button, all without touching the display. Make life easier for yourself and install it on your Windows Phone handset today.
source: GesturesBeta (WindowsPhone) via WindowsCentral