SportCalendar app is an easy to use calendar for your garmin connect activities. It is possible to activate automatic background sync with garmin connect. (Its not possible to enter new activities in this app)
The calendar does show (once available on garmin connect)
Total values for:
-Duration
-Distance
-Accent
-Energy consumption
Average values for:
-Speed
-Heart rate
-Cadence
-Bike power
Metric (km, m) and imperial units (mi, ft) are supported.
The activity list provides a search, sort and filter function.
If you need more detailed trainings analysis and information you might consider sportZones app.