Keep It Simple, Sanitation – experiences of app development

By Rosie Renouf, Research Officer, Water & Sanitation for the Urban Poor (WSUP)

Going to the toilet hasn’t changed much over the last few millennia and the nuts and bolts of the biological side of it are unlikely to change anytime soon. What has changed over the last 20 years of so, though, is our ability to collect reams of information about where we go to the loo, what we do when we get there, and what happens afterwards. Tools like Shit Flow Diagrams give a clear picture of where human waste goes, while organisations like mWater or Gather are pioneering ways of sharing real-time data about WASH.

While the act of going to the toilet hasn’t changed, removing waste safely is getting much more complex as urbanisation pushes more people closer together. WSUP works in crowded, low-income areas that lack adequate water or sanitation, and we recognise that information about residents and the services they can access is needed as much as infrastructure – perhaps even more so.

This blog shares our experience of developing a mobile phone application for the people who work in sanitation in those cities: the business owners who own the tankers that travel across the city emptying full pit latrines and septic tanks, and the employees who drive and operate them. Our main recommendation: keep it simple!

Tech and toilets

The FSM5 conference held in Cape Town earlier this year showcased a wealth of examples of data being captured, analysed and used to improve urban sanitation services around the world. For example, Sanergy, the container-based sanitation company operating in Nairobi, explored using sensors in their Fresh Life Toilets to record use and estimate toilet fill level as a way of improving waste collection.

In two cities in Tamil Nadu, the Tamil Nadu Urban Sanitation Support Programme is tracking and scheduling regular desludging online, with households automatically scheduled for a vacuum tanker visit based on the date that their facility was last emptied. They have also developed an app that monitors urban local bodies’ progress in improving septage management.

The overarching aim isn’t to produce something shiny or to reinvent the wheel – it’s to help sanitation service providers do their jobs and to ensure that as many people as possible can access safe sanitation services. So the real question is: how do we not only collect data but how can it be made useful to those who need it?

Developing a mobile app for sanitation workers

Vacuum tanker operators in many cities often lack information about customers and their septic tanks or pit latrines – the kind of information that is crucial when they need to make important business decisions. For example, some companies may not keep detailed records about when they last emptied a customer’s pit or tank, so their ability to target those customers when pits and tanks are filling up again will be compromised.

Pula was designed to respond to issues like these. A mobile phone application developed by WSUP, BoP Innovation Centre and UX (funded by Bill & Melinda Gates Foundation and VIA Water), Pula aimed to make it easy for managers and employees to keep in touch with each other as they serve customers across the city, to keep up-to-date client records, and to keep track of vehicles.

Read more about PULA

Project team members worked alongside vacuum tanker owners and operators in Mozambique and Zambia to design app features that would make their day-to-day jobs easier and the business more efficient. The feedback about these prototype features were used to develop the next versions, which were shared with target users again. After multiple iterations, a Minimum Viable Product was launched and tested with vacuum tanker businesses in Maputo, Mozambique and Lusaka, Zambia.

The tests revealed that the current MVP is too complicated for the target audience and doesn’t respond well if internet access is unreliable. Setbacks like these are not unfamiliar when you work in a sector as challenging as urban sanitation, particularly when developing brand new products like Pula. Pula will need to be redesigned before going through the test process again – but the lessons learned during the journey so far will certainly inform how we approach projects like this in the future.


The three main takeaways from the development of Pula were:

  1. Reduce complexity: The project team had a lot of ideas for features for the app, which was understandable given the numerous inefficiencies uncovered during the in-depth consultation with various sanitation business owners. However, too many features make the app too complex for the target user. Recommendation: Focus on one core feature, reducing the space for things to go wrong.
  2. Identify your ‘hero’ user: The project team included multiple vacuum tanker businesses in the design research, prototype assessment and app testing stages. In retrospect, it would have been more valuable to embed the whole app development process within one company. Recommendation: Establish strong links and build a relationship with one sanitation business, which will allow for longer testing periods.
  3. Focus on a single market: This was a multi-country project: foundational research took place in Ghana and Kenya; the app’s prototypes were built and tested in Mozambique and Zambia. This meant that the final MVP was the composite of multiple markets and did not answer the specific needs of one in particular. Recommendation: Develop a product in response to one market – this can then be adapted for new markets as required, rather than the other way around.

While fairly simple-sounding, these three main messages were hard-earned – we hope that our experience can help other organisations as they think more about app development in general and sanitation-related apps in particular. Pula is likely to be the first of many WSUP projects that explores app development and other methods of capturing data, given the ubiquity of mobile phones across Africa and Asia; meanwhile, the lead developer of Pula from WSUP is now combining forces with the developer of a similar app that has already had some success with vacuum tanker businesses in urban Mali, helping ensure that insights from our experiences go on to support innovation in another part of the WASH sector.