In March there was a small update released for the Microsoft Dynamics 365 for Customer Engagement On-premise users.
It includes some improvements for working with Microsoft Dynamics 365 on Google Chrome and a few other cumulative updates.
DYN365CE Online gets updated almost weekly with these tiny patches, notice the last four digits of the version (v9.1.0000.3653) so the online folks don't need to think about this one.
It is also worth noting that one of the bigger updates for the year (APRIL 2019) is PACKED with cool and depth. You definitely want to get consuming and embracing the release notes for this release on your To Do List.