Before You Build
Mobile AppShut Down

Tandem

Tandem was a medication-adherence app that struggled to turn a serious health problem into retained consumer use.

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Product snapshot

What it was

Tandem sent medication reminders and let users nominate a companion who could receive SMS notifications if a dose was missed.

Who it was for

people taking regular medicationpatients with chronic medication routinescompanions such as spouses, family members, or friendsfuture payer or pharmaceutical partners

Problem / value

It tried to use reminders and social accountability to support medication adherence.

Core workflow

  • receive medication reminders
  • notify a companion after a missed dose
  • support adherence behavior
  • test social support around medication routines

Product form

iOS appmedication reminder appSMS companion workflowdigital health behavior-change tool

Pricing model

Free to users; planned monetization through pharmaceutical companies and payers was not validated by revenue.

What happened

Summary

Tandem moved from a promising compensated pilot to an MVP app, but real-world adoption and retention were below expectations.

Outcome

Tandem shut down as an active product after failing to prove enough adoption, retention, and monetization path.

Demand signal

The team saw encouraging pilot signals, but the founder later said adoption and retention for the MVP were lower than expected.

Distribution issue

The team launched to pilot participants, disease-specific forums, ads, and healthcare contacts, but paid acquisition was cost-prohibitive and clinician distribution was hard.

Timeline

  • The team recruited 120 American adults for a six-week SMS pilot.
  • The pilot tested reminder, logistics, social, financial, knowledge, and tailored interventions.
  • The team then built an iOS MVP focused on medication reminders and companion SMS support.
  • After launch, adoption and retention were below expectations.
  • The team stopped further development and the app was no longer available on the App Store.

Before you build

Why it matters

Behavior-change products often have delayed benefits, split incentives, and weak daily pull even when the underlying problem is important.

Primary check

Validate adoption, retention, and payer alignment before building behavior-change products around delayed benefits.

Checklist

  • Run acquisition tests before building the full intervention.
  • Measure retention from non-compensated users separately from pilot participants.
  • Test payer or partner interest with concrete commitments, not only theoretical interest.
  • Interview people who tried the product for a few days and stopped.
  • Will users adopt this without study recruitment or compensation?
  • What behavior shows week-one and week-four retention?
  • Who pays if the daily user does not?
  • What immediate moment makes the delayed benefit feel valuable?

Relevant if

  • You are building in health, wellness, education, productivity, or behavior change.
  • Your product depends on users forming a new routine.
  • The user and payer may be different people.

Less relevant if

  • You already have direct payer commitments and measured retention.
  • Your product solves an urgent same-day pain.
  • The workflow is mandatory rather than optional.

Pre-build tests

  • Use a landing page and small paid-acquisition test to measure real demand.
  • Run a concierge reminder workflow with unpaid users and track repeat engagement.

Transferable lessons

  • Treat pilots with recruited or compensated participants as limited evidence.
  • Validate acquisition and retention before building the full app.
  • Do not assume a free user base will later create payer demand.
  • Find a near-term aha moment when the ultimate benefit is delayed.

If you build this today

Test acquisition and repeat use before the app build; prove who pays, who uses it daily, and what near-term moment makes the benefit feel real.