Greendurance (Capstone Project)

An iOS mobile application to encourage eco-friendliness

We all know about the deleterious effects of global warming (Gore, 2006). While there may be quite a many individuals as well as organizations who would try to do something about it, it is not enough. We, as individuals, need to do our part too, even if it is doing something really small. Greendurance, developed as my Capstone project, helps us do that something, whether it is to help us buy eco-friendly grocery products, dispose (trash / recycle / compost) waste, or encourage us to travel sensibly. In short, the app motivates its users to be environment-friendly and reduce their ecological footprint through easy, everyday activities.

Andrew Fellows, my sponsor and the person who put forth the idea for the need for a product that could alleviate the environmental issues, presented me with this fulfilling opportunity. But how could I make such a product accessible to as many individuals as possible?

Discovery phase

According to a study by Pew Research Center in Spring 2015, 72% of adults in U.S. were reported to own a smartphone (Poushter, 2016). Then, why not use smartphones as a medium to inculcate this habit in each individual (that uses the app) and bring about pro-environmental behavior in them? With the support and guidance of Dr. Bill Kules, my Capstone Professor and mentor, and Andy, I went ahead with the idea.



Schedule across the two semesters

The Capstone spanned across two semesters (schedule images above) with the final goal being to develop a product that follows user- centered design principles. My project followed an end-to-end user centered design process.

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Summarizing the papers

Performing a formative study not only prepared me to design the right kind of app, but also helped me acknowledge the knowledge gaps I had, thereby enabling me to ask the right kind of questions to participants during user interviews and through surveys and focus groups.

The key takeaways from these papers were:

  • It is important that pro-environmental behavior be instilled in a larger mass in order to mitigate the environmental issues (Griskevicius et al., 2010)
  • Ways to start locally could include traveling sensibly, cutting down on waste, saving energy and natural resources, preventing pollution, and looking after the local environment (Collins, 2004)
  • Activating the motive status in people could get them to perform ‘green’ actions (Griskevicius et al., 2010)
  • Green gamification could be used as a persuasive technology to bring about pro-environmental behavior amongst its users (Froehlich, 2015)
  • Providing feedback to users about their performance is an important intervention technique (Marcus et al., 2009)

Comparative Analysis

Additionally, a comparative analysis of similar existing mobile applications was performed.

Tabular representation of comparison
Tabular representation of comparison

The comparison in the above table was done based on the features the Capstone project aimed to provide during the discovery phase. Each of the above applications were pretty good and were selected because they provided features and facilities very similar to the ones that were to be included in the project.

Initially, only the above mentioned features were planned to be added to the app. However, after conducting user interviews, focus groups and surveys, the key features to be included were changed to ‘shop green’, ‘dispose right’ and ‘ride clean’ (explained later).


A survey was conducted in two rounds; one, sent out to friends and neighbors, and based on the feedback from the first, the questions were rephrased and rolled out as a second slot to neighboring communities as well.

The survey aimed at gathering information about participants’ grocery shopping, trash disposal and transportation habits. Through a mix of open-ended as well as closed-ended questions, I was able to get an idea as to why participants did or did not perform environment-friendly actions.

While the survey really helped getting started with the idea, a deeper insight was needed into the participant’s environmental psychology and what they looked for in a gamified mobile app. Therefore, user interviews and focus groups were decided to be conducted.

Focus Group


During the discovery and design phase of the project, I attended the Committee for Better Environment’s monthly meetings. The members were very helpful and offered to provide some really useful suggestions for my app. While it wasn’t a formal focus group as such, I was able to collect some really great ideas from the group.

Additionally, the members assisted me with evaluating the high-fidelity prototype of the app and provided feedback for the proposed design.


User Interviews


By conducting user interviews (over Skype), I was able to collect rich data and gain deeper insights into the environmental psychology and mobile app preferences of the participants.

Through the interviews, the key points learned were:


  • Participants felt that eco-friendly products are expensive and not affordable when compared to equivalent non-eco-friendly products
  • In addition to incentives for users, social element was an important feature to be included in a gamified application. It allowed users to indulge in a healthy competition with their friends while constantly comparing their performance with those of friends, thereby increasing user participation
  • Awareness about current environmental issues and their impact on living beings was lacking amongst most participants


Additionally, the need for an easy way to distinguish trash from recyclable and compost items was necessary. Also, while purchasing groceries, since price was an issue, a mechanism needed to be developed which would urge users to purchase more eco-friendly products. Similarly, when it came to transportation, convenience was what resulted in non-green transportation habits.

Another takeaway was that users preferred simple, clean, minimalistic yet attractive applications that were not too complex for the user to understand and use. Also, making the goals clear to the user as well as achievable was important.

The participants mentioned a few apps that they liked and a few that they disliked. This helped me learn from other apps as to what works and what doesn’t


Design Phase


Low-Fidelity Prototype


Low-fidelity prototype of the app


The first step to using all the data collected during the discovery phase and applying it into a design was to create a low-fidelity (paper) prototype of the app. This method was chosen as it was quick, inexpensive and effective.

Following were the features offered to be provided by the app at this stage:


  • Shop Eco: Use this feature while in a grocery store. It is not linked to the store’s system in any way, but provides a list of common grocery items along with a scale of how eco-friendly the product is. More the eco-friendly, more the number of points a user would get on acknowledging that that product was purchased. User can barcode scan a product too for quick access to information about that product.
  • Transportation: A list of ‘green’ transportation choices that users can refer to, perform and gain points for, once checked
  • Waste Disposal: A search for an item that the user would want to dispose would display information about which bin that item should be disposed into, based on its packaging. The user can also use the camera option for an augmented reality feature which when focused on an item, detects it, and pops up disposal information about that item. The disposal reference cards as seen at the University can also be referred to
  • Friends: An ability to add friends and track their score, for comparison and healthy competition
  • Eco Facts: Facts about global warming and how it is affecting the environment. Additionally, it would also include tips and ways to reduce one’s ecological footprint
  • Badges: List of badge collection earned by the user

  • Ranking: User’s ranking with respect to all other users of the app

Participants evaluated the prototype and provided really useful suggestions as well as pointed some critical issues with the design too. This helped me modify my design, correct the discovered issues and improve the design.

Some of the areas of improvement included:

  • After sign up, directly login the user into the app
  • Add ‘Badges’ link to the bottom menu instead of the sliding menu for easy accessibility
  • Icons need corresponding text / title to understand what feature it represents
  • Create an additional screen or popup to congratulate user with feedback of new score, on performing agreen task
  • A ‘help’ icon at the top of key features to help new users understand how to use the feature
  • ‘Shop eco’ which was short for ‘Shop Eco-friendly’ was mistook for ‘Shop Economical’
  • Adding a friend was not very clear and usable

High-Fidelity Prototype

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Using the feedback received from the low-fidelity prototype evaluation, the design was modified and a high- fidelity prototype was created using Sketch3 and InVision. The design was evaluated for further improvement.

Some of the suggestions included:

  • Improve home page and add a dashboard (for easy access to user stats) instead of a fact
  • Search bar not required for the ‘Transportation’ feature as the list will not be too long
  • ‘Ranking’ and ‘Badges’ don’t exactly belong together. Separate them

Implementation Phase

Home Page of the app



The iOS app was built using Xcode and Swift. Having no experience in this domain, I spent a few months going through online tutorials in order to be able to build the final app in iOS. I faced many technical challenges along the way, but who doesn’t? In the end, I conquered it all and enjoyed the over all experience.

The features provided by this gamified app that I call Greendurance (‘Green’ as the environment hopes to be; and ‘Durance’ as we would have to endure all challenges that come our way in order to restore the environment to its safer and cleaner state) are as follows:


  • Shop Green: This feature provides a list of commonly purchased products at grocery stores (used partial data from dataset provided on the website). The users can tap on the products they purchased and earn points for each purchase (more points for more eco-friendly products). Furthermore,

    the users can optionally provide their own rating for the product’s eco-friendliness (on a scale of 5) as they perceive it to be.


  • Dispose Right: Once the user taps on products from the ‘Shop Green’ feature, each of these products, based on their packaging information, are added into 3 sections – ‘Trash’, ‘Recycle’ and ‘Compost’. This helps the user make quick disposal decisions after they have consumed the product, and they earn points for disposing them in the right bins. Additionally, the disposal cards, as found near the University of Maryland bins, can be viewed for all other waste items.


  •  Ride Clean: This feature suggests several clean ways of traveling, with each having a certain number of points for grabs. This encourages users to travel by one of the mentioned ways in order to earn points.


  • Badges: One of the key elements of a gamified app is to incentivize its users. On earning a certain number of points, the users of this app are awarded badges as an incentive and a way to appreciate their efforts. This way the users would feel valued and motivated to do even better.
  • Facts and Tips: In addition to the fun elements of the game, the users are also exposed to facts and tips related to the environment and how to protect it. Awareness, being one of the main issues as mentioned by some of the user interview participants, it was necessary to include this in the app. Each of the facts included in the app have been taken from external links with credit given to each, on the app’s credit page.


  • Social element: Being connected with friends and showing off achievements to them was critical to the success of the app. According to the data collected during the discovery phase, it was learned that having such a feature encouraged its users to perform better in order to look socially attractive (Griskevicius et al., 2010), allow users to compare their performance with their friends’, and encourage healthy competition amongst the users (Froehlich, 2015). Users can add friends and monitor their score. They also get to see their ranking with respect to all the users of the app. This was mentioned to be a required feature by participants during the prototyping sessions. (Note: Celebrity names have been used as names of users of the app. This is only for testing purpose and is used as dummy data.)


  • Progress tracking: The ‘ranking’ and ‘lifetime progress’ elements of the app allow the users to maintain short- as well as long-term goals, respectively. Checking the ranking against other users would motivate the users to perform more environment-friendly actions in order to get their score up. However, this would be a short-term goal as it may not take too long for a particular user to get to the top. After getting to the top, the user may grow weary of using the app and may stop acting ‘green’ altogether. Therefore, a long-term goal tracking system is also needed. This is where the ‘Lifetime Progress’ bar could help. It acts as a means by which the users can keep improving their current progress.


A few challenges that I faced while working on my capstone included technical issues (bugs), spending a lot of time fuguring out how to implement completely new and unrelated functionalities, and having to settle with a minimum viable solution for certain features. Additionally, towards the end, it was a little difficult to get enough participants to perform a usability test of the final prototype. However, in the end, I was able to get sufficient number of participants.

A user trying out the final app

The usability study involved asking the participant to perform certain tasks using the ‘think aloud’ method, capturing subjective as well as analyzing quantitative metrics (“Reporting Usability Test Results”, n.d.), and making changes to the app accordingly. It was an iterative process (1 informal and 2 formal rounds of usability testing) with the goal of producing an app that is user-centered.

Following were the tasks the participants were asked to perform:

  1. Sign up and explore the app
  2. Assume you were at a grocery store and bought products X, Y and Z. You want to find out how eco-friendly a product is perceived to be, and accordingly, make your purchase. Earn points for purchasing it.
  3. Assume you took metro to work today. Grab the opportunity to earn points for it, if you think you travelled in a considerably environment-friendly way.
  4. You just finished consuming the product X that you bought the other day from the grocery store. Use the app to find out which bin to throw its packet in.
  5. You feel quite lonely using the app and therefore, want to add a friend and probably even track their progress. Go ahead and add your friend named John Doe.
  6. Check out the badges you’ve earned so far.
  7. How does your total score compare against that of your friends?
  8. You are keen on reading some articles on global warming. Find if the app has any facts that you could read?

Each task was monitored and their metrics were captured (with guidance from These metrics included:

  • Task completion rate
  • Time on task
  • Errors (critical and non-critical)\
  • Subjective metrics (related to ease of use for each feature)

There were a few critical issues during the first round of usability testing. First issue was that the barcode scanner was not easy to use (button was not easily clickable and did not detect the barcode properly) and second issue was difficulty signing up (the app did not warn the user about the minimum password requirement). These issues were fixed and a second round of usability testing was performed. There were no critical issues during the second round, and participants were pleased to use the app.


Since I did not have any experience developing mobile applications, this project was challenging but a lot of fun. I started off feeling a little lost as to what features I should add to the app. But through the Capstone project, I learned how important user interaction is, and the data one collects using a combination of several HCI methods.

While conducting user interviews, I got amazing suggestions and ideas during the very first user interview itself. I almost felt like not conducting any more user interviews, but I still went ahead. And each user interview shed light on a different perspective thereby exposing several different personas users of this app could have. This helped me design something that could be useful for each of these personas.

Designing and producing a product that is the creator’s vision doesn’t really help if your user just doesn’t find your product useful or, even worse, usable. I learned that designing your product for the user with the help of the user (through interactions) would get you to build something that is actually usable and well-appreciated too. The entire process takes a lot of time and effort, but the outcome is worth every penny and a return on your investment.

Future work

I would mostly continue adding new features to the app to make it even more attractive. Andy suggested some great ideas that include enabling users to find the right solar energy solution for their homes. Additionally, I would enable more interactivity amongst users through an internal messaging tool, or the ability to post achievements to Facebook, Google+ or some other social networking site. Furthermore, a feature to allow users to locate the nearest farmer’s market seems like a good idea.


My vision for this app is for users to have fun while they (knowingly or unknowingly) work towards achieving a serious goal (of reducing their ecological footprint). I really hope the app does justice to this vision. I would certainly want to add new features to make it more than a minimum viable product than it currently is.

While the entire process, of building a product that is user-centered, was challenging, I ended up learning lot more than I thought I would, and I enjoyed every step of it. The formative study helped build a foundation to my understanding and knowledge, the user interactions helped me design and develop a product that was usable and useful, and I personally, benefitted by adding a new technical skill to my skillset too.


Collins, A. J. (2004). Can we learn to live differently? Lessons from Going for Green: a case study of Merthyr Tydfil (South Wales). International Journal of Consumer Studies, 28(2), 202-211.

Froehlich, J. E. (2015). Gamifying Green: Gamification And Environmental Sustainability. The Gameful World, 563-596.

Gore, A. (2006). An inconvenient truth: The planetary emergency of global warming and what we can do about it. Rodale.

Griskevicius, V., Tybur, J. M., & Van den Bergh, B. (2010). Going green to be seen: status, reputation, and conspicuous conservation. Journal of personality and social psychology, 98(3), 392.

Marcus, A., & Jean, J. (2009). Going green at home: the green machine. Information Design Journal, 17(3), 235-245.

Poushter, J. (2016). Smartphone Ownership and Internet Usage Continues to Climb in Emerging Economies. Pew Research Center: Global Attitudes & Trends. Retrieved from smartphone-ownership-and-internet-usage- continues-to-climb-in-emerging-economies/

Reporting Usability Test Results. (n.d.). Retrieved from

All icons used from