Hi Will! What's your background, and what are you currently working on?
Hi! I'm Will and I'm a software engineer / product manager from San Francisco. My co-founder Peter and I are currently working on a weight loss coaching app called Intent, which helps people lose weight through small changes.
We previously worked on Tandem, an app to help people stay on top of their medications. We tested our hypotheses in a 120-person pilot and built an MVP of our app, but found that adoption and retention weren’t what we expected.
What motivated you to start Tandem?
My co-founder and I are interested in health behavior change - we previously spent time doing research in molecular biology and behavioral economics - and we knew that many people don't always take the medications they're supposed to (ourselves included!). Over 60% of American adults are supposed to take at least one medication daily, but half of them don't. The common estimate is that medication non-adherence results in up to $300 billion in avoidable health care costs.
We talked with professors, conducted surveys on Mechanical Turk, and spoke with individuals who take medications regularly. The more we looked at the problem, the more we felt like there was a gap between the research behind medication adherence and the solutions available in the market.

Most people will say they didn't take their meds because they forgot, but that's usually cover for a larger set of underlying reasons (e.g. they don't trust their doctor, aren't sure why they should be taking the meds in the first place, don't have the time or money to fill their prescription). Given that non-adherence is a multi-faceted behavioral problem, we believed we needed to develop interventions that would address each of these challenges.
How did you build it?
We wanted to first test our thesis: that tailored interventions would actually help people take their medications more regularly, and that people would be interested in that help. We recruited 120 American adults on Mechanical Turk, all of whom took medication regularly for a chronic disease and had access to a cell phone, and ran an SMS-based pilot for six weeks.
We segmented the group into six categories:
- Control: SMS medication reminders only
- Logistics: reminders + help refilling medication, pill organizer
- Social: reminders + support group or help from a companion (e.g. spouse, family member, friend) via SMS
- Financial: reminders + lottery incentives based on adherence
- Knowledge: reminders + content about their medications and chronic illnesses
- Tailored: all interventions
We built a custom admin tool to help us manage sending and receiving SMS through Twilio, wrote custom SMS content, and constructed an automated system to send out reminders, replies, and scheduled content.

We also asked participants to complete pre- and post-study surveys, which were compensated. User satisfaction was high throughout, the dropout rate was surprisingly low, and we observed that intervention groups - particularly the "tailored" group - had improved adherence (adherence improvement was almost 2x the improvement observed in the control group). Many of our participants appreciated the various interventions we delivered:
- It was a really good thing to have my daughter involved. It was a bonding experience; I felt that she learned more about my illness (diabetes) and she helped encouraged me to learn more, too. And when she sent me those little notes of congratulations about doing well taking my meds, well...that was priceless!
- My wife was able to get plugged into the medication discipline without feeling that she was nagging me, so it was positive.
- I will be very sad to see the daily reminders go. I will have to re-install one of my alarm apps, and they just don't have the same effect.
- After reading the lesson, I think twice now about eating a sugary product. The damage that sugar can do is a real eye-opener.
- I kinda missed getting the text the last few days, it made me think about why that was. I think this texting service would be perfect for an older person, living alone. Not only as a reminder to take their medications, but to make them feel less alone while dealing with their health issues. I'd even consider volunteering to work as such a service if there was one nearby.
Based on these results, we felt we were moving in the right direction, so we decided to build an initial MVP of an app that would begin to deliver these same interventions. We picked social support as our first feature. We offered the app for free and planned to grow a base of free users. As we built out the product, our monetization plan was to partner with pharmaceutical companies and payers (e.g. insurance companies) who would be interested in solutions that would be adopted and can genuinely improve adherence.

We designed and developed Tandem, an iOS app that offered medication reminders and also allowed you to specify a companion who would be notified by SMS if you didn't take your medication.






