Graphical User Interface (GUI) testing is a relevant step of the software development process which is not often performed thoroughly due to its unappealing nature, to the inherent fragility of test cases, and to the fact that test cases – com- posed of long and complicated sequences of operations – have to be manually written by testers. We propose GERRY , a Capture & Replay GUI testing tool which implements an approach based on Gamification, i.e., the application of gaming elements to non-ludic activities. The purpose of the tool is to increase the engagement of the testers when performing GUI test case definition tasks. The tool makes use of mechanics typical of games such as progress indicators, leaderboards, and unlockable rewards, to increase user interest and involvement. GERRY also gener- ates reports (i.e., traces of all actions and milestones reached during a session), written logs of the performed testing ses- sions, and scripts compatible with existing GUI testing tools (SikuliX and Selenium) for replay purposes.