We have recently moved the Flexwatch function in the Hopper app! You can access it when searching for a roundtrip flight to any location on the calendar search page. Click on “See Flex Dates” which will allow you to create a Flexwatch. You can customize this by clicking on the pen icon on the top right-hand side of the screen. Please see below for an outline of how to set this up!
Please note that the Flexwatch function is only available for roundtrip flights and for iPhone users at this time.