iPhone Screenshots


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

Drfudo ,


Doesn't open on iOS 10.1.1 iPhone 6s Plus

Jdetmold ,

Not for real world

This is a neat app and I'm sure on paper it would work great but as far as usability in the real world it's useless. If it were able to take into account the time the sun is up and a scheduled for work when you can't sit in a dark room this would be helpful. But if I am traveling with an 8 hour time shift back home I can not sit in a dark room for 16 hours on a work day. It's just not practical.

warbitrary ,


Problems: 1) When setting a schedule, the “Schedule” and “Clear” buttons are close together on a 3.5” screen, resulting in frustrating misstaps. 2) Changing timezones between origin and destination is clunky and slow. Why not just have a quick toggle instead of a lengthy time zone selection process? 3) After I setup the app with my time zone, I scheduled a trip, and the app changed my origin timezone without telling me, resulting in an incorrect schedule. 4) For a trip to Europe, the app recommends light exposure at 5:20 and darkness at 19:30, Europe time, which doesn’t make any sense, since the sun rises at 6:30 and sets at 20:50 at this time of year. Maybe there is good reason for this, but at first glance it seems to shift too far.


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

    Up to six family members will be able to use this app with Family Sharing enabled.

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