Most people do not realize how high a percentage of missionaries do more than preach the Gospel or build churches. For instance, the Cyrillic alphabet is named after Saint Cyril. Yes, I am aware that neither SS Cyril nor Methodius invented the Cyrillic alphabet. However, they did invent the Glagolithic alphabet that becomes one of the foundations of the Cyrillic alphabet. Just another nice service of missionaries. From literacy through clean water through schools through orphanages through hospitals, etc., missionaries have always done much more than simply preach the Gospel. My wife and I had Third World solar cells on the roof of our house in Arequipa in order to help heat our water tank.
As a result, if you read about the churches of the Global South, you most often see churches that not only preach the Gospel, but are also strongly involved in various types of social work. I know of at least one church group in Perú that is/was (I have been away for too long) involved in making micro-loans to people trying to start small business. Though I have strong theological disagreements with the Seventh Day Adventists, and think that one of their factions has stepped too far outside Christian teaching, yet they have an incredibly large healthcare work in Perú.
One of the large problems is that of clean water. And, yes, the toilet above will help solve some of those problems. As a former missionary, I am glad to see the invention above.