I often hear that sometimes customers need to have custom reports created for their CRM online version which are
more complex than native CRM reports which can be generated using Wizards.
CRM on premise supports SSRS based reports written in SQL whereas CRM online supports Fetchxml version,
which needs expertise to develop.
This post outlines an offering for custom development done by CRMIZERS:
Also, all the reports have been provided as samples in downloadable formats.
For further details on custom report development you can contact on firstname.lastname@example.org or check
Hope it helps and Happy CRMing!