Hand rehabilitation requires intensive training with various gross and fine movements. Thus, rehabilitation robots for the hand that accommodate for the different degrees of freedom are often complex and expensive. This work presents the design of a portable plug-and-train robot (PLUTO), which tackles the problem by having a single actuator that can be coupled with different passive mechanisms for training wrist flexion-extension, ulnar-radial deviation, hand opening-closing, and forearm pronation-supination. The robot is capable of providing training in active and assisted regimes. Training is through performance adaptive computer games to provide feedback to the patients and to motivate them during training. The usability was evaluated in patients, caregivers, and clinicians with standardized questionnaires: System Usability Scale (SUS) and User Experience Questionnaire (UEQ). Patients and caregivers were administered the questionnaire after two training sessions. Clinicians, on the other hand, had a single session demo after which their feedback was obtained. In this paper, we present the initial results of 5 clinicians, 5 caregivers, and 5 patients. All groups found the system to be highly usable (180 scores on the system usability scale). Furthermore, the scores from UEQ feedback were all positive, and all groups found the system attractive. The patients and the clinicians rated the system positively in both pragmatic and hedonic scales. We believe that a simple approach proposed here can result in a compact tool with a high benefit-to-cost ratio for both in-clinic and home-based hand rehabilitation. © 2020 IEEE.