There are 26 million smartphone users in South Africa - In the whole of Africa, there are only 22 million Twitter users.

There are 650 million cell phone users in Africa - that's, more than half the population. Again, in the whole of Africa, only 22 million people use Twitter.

For the record, in the entire world, there are only 450 million Twitter users, out of a population of 8 billion people. America has the highest number of users - 23%. That's not even half.

It is NOT a popular (nor useful) app. It most certainly is not a popular app in Africa where, even if you only use a percentage of the people who actually own a phone, it's under 3% - which you did not specify.

You need to check the actual statistics before you make a statement - not base it on your own experience.

I first started using the web in 1994 when I worked for a publisher in Johannesburg. I have lived and worked in the US, the UK, and the EU.

https://www.statista.com/statistics/488376/forecast-of-smartphone-users-in-south-africa/

https://www.un.org/africarenewal/magazine/may-2013/africa%E2%80%99s-mobile-youth-drive-change