WhatsApp

 WhatsApp  is a proprietary mobile messaging application and is owned by Facebook.

WhatsApp is extremely popular in Russia, Brazil, Mexico, India, Spain, Italy and Germany, and amongst the geographically dispersed migrants from those countries. One of the driving forces for the popularity of WhatsApp is that it is often significantly cheaper to send messages via a data plan (or wifi) than it is to pay the excessive rates that some countries charge for sending messages via SMS. WhatsApp does not support third-party clients or chatbots.

It has been repeatedly blocked in Brazil by court order. In Brazil, WhatsApp is used as a popular form of social media: a lot of people use WhatsApp for large group messages to distribute links, memes and videos, many of which are political or social in nature. The blocking of WhatsApp in Brazil is more blocking a "broadcast" social networking site like Twitter than it is like that of a person-to-person messaging service.

How to POSSE
is considering POSSEing to Whatsapp to let people follow her without forcing them onto other services. knows about a possible way to do so: https://github.com/hoehermann/purple-gowhatsapp or https://github.com/sigalor/whatsapp-web-reveng for a description of the API

WhatsApp Web client
WhatsApp has a desktop/web client. Due to the way end-to-end encryption is implemented in WhatsApp, this is not a true fully-fledged client. All messages sent using the web client are sent first to the user's phone and then sent on from there. It does not work without the mobile client. This means that it won't work if your phone has run out of battery or you wish to access your WhatsApp messages in a country where you do not have mobile service.

The afterthought feeling of the web client is in part because WhatsApp has found most of its popularity amongst users, and in countries, where PC ownership is low compared to smartphone use.

2015 Brazil
WhatsApp was blocked in Brazil for ~12 hours (of original 48 hour order).

2016 Brazil
WhatsApp blocked in Brazil for ~1 day (of original 72 hour order).

2022-04-28
Outage around the world 2022-04-28: WhatsApp is currently down for multiple users around the world "The popular messaging app WhatsApp, which is owned by Meta, is currently down for multiple users around the world. There seems to be a widespread outage that has been preventing users from accessing the platform as of Thursday afternoon."

Criticism

 * 2015-01-21 Andre Garzia: WhatsApp doesn't understand the web
 * Whatsapp blocks links to rivaling messenger telegram:
 * 2015-07 WhatsApp, Instagram and Facebook account of third-party WhatsApp API developer blocked