Today I'm listing 4 of my useful SSIS third party tools
1-BIDS Helper, The variables extension is an amazing and a must tool for changing the variable's scope http://bidshelper.codeplex.com/
2-Validate, create and test variable outide BIDS SSIS Expression Editor & Tester
3-SSIS Component Explorer http://www.sqllion.com/2009/06/ssis-component-explorer/
4-SSIS Log Analyzer http://ssisloganalyzer.codeplex.com/
Hope that helps.