A tablet computer with modular assembly or smartcase having interchangeable accessory cap portions, and a method for using the same to monitor environmental conditions around the tablet computer and smartcase. The smartcase provides a universal design and customized features to a range of tablets. The smartcase has a tablet carrier connected to selected type of tablet computer and an exterior housing connected to the tablet carrier. The exterior housing/cap contains at least one battery, a memory, sensor(s) and a controller for communication with the selected tablet computer. The housing also includes accessory cap portions configured to communicate with the controller and implement a function. The data collected by the sensor(s) is utilized to monitor conditions associated with the smartcase such that preemptive or corrective action regarding the smartcase and/or tablet computer may be implemented. The smartcase can also include one or more programmable LED buttons and/or indicators.