Model-based selective regression testing promises reduction in cost and labour by selecting a subset of the test suite corresponding to the modifications after system evolution. However, identification of modifications in the systems and selection of corresponding test cases is challenging due to inter-dependencies among models. State-based testing is an important approach to test the system behaviour. Unfortunately the existing state-based regression testing approaches do not care for dependencies of the state machines with other system models. This paper presents the tool support and evaluation of our state-based selective regression testing methodology for evolving state-based systems. START is an Eclipse-based tool for state-based regression testing compliant with UML 2.1 semantics. START deals with dependencies of state machines with class diagrams to cater for the change propagation. We applied the START on a case study and our results show significant reduction in the test cases resulting in reduction in testing time and cost.