WeChat is an application that allows users to communicate through different mediums. They currently are available on multiple platforms: iOS, Android, Blackberry, Windows, Nokia and any web browser.  WeChat is created by Tencent Holdings Limited, a listed technology company based in Shenzhen. It was launched in January 2011 and has surpassed 100 million users by March 2012, outpacing Facebook and Twitter.  Now it has around 400 million active users. 
- Push to Talk
Users can push to talk to send a voice message. Sending a voice message allows the person to have a more personal connection by giving out more social cues like tone, volume of the voice. The maximum length of a voice message is 59 seconds. The user can click on the voice message to and decided whether to listen to it on "handset mode" (by holding the phone as if you are calling someone) or on "speakerphone mode" (by pressing the voice message). If one made a mistake while recording a voice message, one could easily swipe up and delete what one just recorded. This is a popular function of WeChat and is a main reason how WeChat became so popular.
This is similar to Instagram, with users sharing pictures to a private group of friends. In addition to pictures, you could also share statuses and Web links. The main difference between WeChat's moments and Instagram is that you can only see the "likes" and "comments" by your friends. Only the user could see the total count of likes and the comments. This makes "moments" more privatised.
- Video Call
Similar to Facetime, WeChat also has its video chat function. The advantage of using WeChat over Facetime is that one could video across different mobile platforms.  For example, an iPhone user could video chat an Android user.
- Walkie Talkie
One could start a "walkie talkie" session with other pals or within a group. Anyone who joins could hear the other person speak when the button is pushed down.
- Drift Bottle
One could throw a virtual "bottle", containing either a voice message or a text message, into the "ocean". Some person (could be other side of the world) could go into the "ocean" and collect this bottle. This person could then choose to ignore or reply.
Ways to add WeChat contacts
1. Mobile Contact If your friend's mobile number is bridged with his/hers WeChat account, one could automatically see him/her in the contact list and could decided whether to add him/her.
2. QR Code Scan Every account has its own QR (Quick Response) code and a after a simple scan a user could add a new pal.
3. WeChat ID If the person has a WeChat ID then one could search for him. When adding someone on WeChat acceptance by the user is needed. If a user finds someone that they don't want, they can easily block that person as a safety precaution.
4. Radar If the person is within a 1 km, Radar allows them to find each to other if they are pressing the "radar" button. This could also be done within a big group.
WeChat combined the functions of SMS, Facebook, Instagram and Skype. Tencent has invested a lot of money into global expansion since 90% of its users are still based in Mainland China.  Tencent is also looking to incorporate social games into WeChat. Currently only Chinese users can play a game called "Shooting Airplanes" and it has already generated a significant amount of revenue. "Shooting Airplanes" allows you to shoot airplanes then compare your scores with friends. This sort of competition creates an online community where people can associate by playing the game on the app.
WeChat has been a big hit especially in Asian countries primarily due to the "push-to-talk" function. Chinese characters are generally more complicated than alphabets and take longer to type. For example, in the word "Apple" only requires five strokes. However, in Chinese, "苹果" requires fifteen strokes. It would be a lot easier to say "apple" in Chinese than to type it out. Also, people are starting to prefer the voice function before it delivers more social cues, allowing people to have a more intimate feeling with the opposition. WeChat focuses the circle of interaction on a set of key people that users actually interact with on a day-to-day basis.
Chinese people primarily use the smartphone for entertainment and fun and WeChat is perfect for it. WeChat have emoticons (usually in cartoon style) which allows users to communicate in a more entertaining way. Also as I mentioned above, WeChat has been popular in China due to its funky ways of adding other users (including shake, drift bottle etc.).
WeChat has conquered the Chinese social media market but now it is trying to take a step closer to penetrate the international market. Already, they have set up an office in Silicon Valley containing around 10 employees. They have also signed the Footballer Star Lionel Messi in order to attract Latin American European users.
- WeChat Launch event in India
- Direct source from Tencent company.
- WeChat Corporations