Seeking Two-Way Syncing Calendar App for Android

A user is looking for an Android calendar application that offers two-way synchronization. They currently use Rogers/Shaw webmail calendars and have encountered issues where appointments added on their Android phones and tablets do not sync back to their Windows laptops. This requires manual re-entry on the laptop to ensure synchronization across devices and with their wife's devices. They are open to trying new apps and are seeking recommendations for Android-compatible or cross-platform solutions.