Double Happy 

Double Happy is a social Tennis Doubles event organizer. It makes it simple and even fun, to run social doubles events for Tennis or any sport or activity played with partners. Double Happy assigns, round by round, a mix of players for each court.
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Professional Tournament Organizer 

FREE Tournament scheduling software and organizer. The system will do knockout and round robin tournaments with auto generating draws and the auto generated time schedules as well as tournament costs.
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TennisManager 

full featured application to manage your tennis- or squashcenter free help from the developers for purchasers free updates for purchasers
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