Dirk, it sounds like what you're looking for doesn't exist yet -- HR monitoring with the Band is pretty under-utilized at this point. Like you've discovered, the phone Health app and the Dashboard offer a day view (under Calories and Steps) but there aren't many other options. The only ones I've found include:
- average HR while sleeping
- detailed HR during runs, workouts, etc.
- and yeah, that's it
There is another option you might check out...on the Dashboard, if you click on your name you'll see "Export your data". After doing that and downloading the Excel spreadsheet, I noticed under the first tab ("Daily Summary") that there are columns for "HR_Lowest," "HR_Highest," and "HR_Average" on a daily basis.
Hope some of that helps!
-Matt