1. WhatsApp 信使：
WhatsApp Messenger，或简称 WhatsApp，是 Facebook, Inc. 旗下的跨平台消息传递服务。它允许用户发送文本消息、语音消息、进行语音通话、视频通话、共享图像、文档、用户位置和其他媒体。
2. 振动：
Rakuten Viber，或简称 Viber，是一种跨平台的 IP 语音和即时消息软件应用程序。它允许用户在任何地方与任何人交换图像、视频、免费和安全的电话和消息等媒体。
WhatsApp Messenger 和 Viber 的区别：
| Viber | |
|---|---|
| It is owned by Facebook, Inc. | It is also owned by Japanese multinational company Rakuten. |
| It was launched on 3rd May, 2009. | It was launched on 2nd December, 2019. |
| Whatsapp allows to personalize the appearance of the app like choosing a different theme or colors. | Viber requires a Gmail login to get started. |
| Whatsapp is add free. | Viber is not add free. |
| There is no option such that an image which automatically disappears once the person has seen it. | In Viber you can send an image which can disappear once the person has seen it. |
| In whatsapp there is no facebook sign in option. | In Viber there is a facebook sign in option. |
| In whatsapp you can set notifications to snooze mode if you don’t want to be disturbed during a specific time frame. | In Viber you cannot do so. |
| In whatsapp maximum of 256 persons can be there in a group. | In Viber maximum of 200 persons can be there in a group. |
| Whatsapp messenger has no cloud sync. | Viber has cloud sync. |