Garmin Connect Calendar is a pretty neat feature where it allows you to plan your workouts days, weeks, or months ahead. However it does not come with a good sharing feature as you will have to download the calendar in order to share it with others.
Hibernate with Spring JPA along with Spring Boot makes it easy for user to manage their database connection. However there are certain column type that is not mapped by default by Hibernate. For an example column type nvarchar in MSSQL could lead to an exception.