Cross platform Wechat application which is very similar to Whatsapp is now updated to version 4.0 and provide you a HD calling support
What’s New in Version 4.0:
– Free HD video calls.
– Support for video messages: record a video and share it with your friends or loved ones.
– Play audio messages in Handset Mode to keep your messages private.
So if you have installed we chat then update it now for better call quality.