: ".anom" is not a standard file extension for Fitbit devices (which usually use .TCX, .GPX, or .FIT). It could be a specific internal naming convention for a data export or a localized software bug.
: You can download your own data via the Fitbit Settings page. Fitbit.anom
: If it is a file, try opening it with a basic Text Editor (Notepad or TextEdit) to see if it contains readable data logs. Fitbit.anom