Features:

• The Designer is using the infrastructure from Windows.Forms.Designer
• Run Expressions inside a Report; based on the work of  Irony and Simpleexpressionevaluator
• UnitTests for many  (increasing number) of Classes

The Designer in Action:

 TextEditor, useful to enter some text and/or expressions:

A very simple report in List layout with PageNumber in the PageFooter section and Aggregate function count() in ReportFooter:

Some more functions:
Line 1 (middle):   nothing to evaluate – (right) concat two fields
Line2 (middle and right):  Userfunctions
Line 3 (middle and right) : Globalfunctions
Line 4 :     show parameters inside report, useful for queries
Line 5:     simple calculation
Line 6:     etc, some more functions

 The Result: