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Entrain is a mobile application that uses your lighting history, activity, and heart rate to recommend schedules of light and dark. These schedules are able to shift a model of the circadian clock to a new time zone as quickly as possible. Users can opt-in to share their data with the University of Michigan for research purposes.

What's New

Version 3.4

Added more explanations, bug fixes

Ratings and Reviews

3 out of 5

6 Ratings

6 Ratings

One Day recovery


I followed the directions to the letter, though difficult on a flight from Australia through New Zealand, ending up in San Francisco. Aside from a few uncomfortable moments, my jet lag was minimal. A good tip is to use a light box to help with the “seeking light” part of the program as I returned in winter, and it still gets dark early in SF. The program is greatly improved in simplicity since I tried to use it last.

Glitchy and difficult to use


I tried to use this to avoid jet lag on a trip with a 17 hour time difference. On the way out, the light suggestions were very challenging. The app wanted me to avoid light during all of my waking hours and had the “seek light” time for only a handful of hours while I was asleep. On the return they app became glitchy and kept changing the times to seek and avoid light by a few minutes or a few hours over the course of the day. It was so annoying. Then it added 5 days to the cycle on the last day and I gave up.

Fix the light scheduling nightmare

Irena the avid traveler

The new Entrain interface is a nightmare. I've been relying on the app for years to avoid jet lag during trips to Europe and Asia. As a token of gratitude, I always submitted data to the U Mich group.

In the past, adjusting the light schedule was a breathe. Now it's a baffling horror, which must be fixed. If necessary, bring back the old version, but interface must be user friendly. Your fans and new users would appreciate it.


The University of Michigan
45.9 MB
Requires iOS 9.2 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© The Regents of the University of Michigan


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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