section is the main page you interact with, use the 'Add A Reading' button to add a new record. By default, records are shown latest first.
Each measurement is colour coded to indicate where the reading falls, either low, good, moderately high, or high.
At the top of the Log page, you'll see you can chose whether you want to filter your readings.
The default is 'All Time', but you can also choose to show values for today, mornings, afternoons, or the previous week.
The average displayed on the log page is what is used to provide basic feedback on your blood pressure. This average changes depending on this filter criteria you chose, so you can easily see your average over all time, just the mornings, or just the previous week etc.