MS Compact Maestro is a top-class SQL Server Compact management and development tool.
Key features include:
Support for SQL Server Compact 3.5 and 4.0
Easy database object management
Data management: editing, grouping, sorting and filtering abilities
Handy SQL Editor with code folding and multi-threading
Visual Query Builder with support for subqueries and UNIONS
Data export/import to/from the most popular formats
Powerful BLOB Viewer/Editor
The application also provides you with a powerful set of tools to edit and execute SQL scripts, build visual diagrams for numeric data, compose OLAP cubes, and much more.