Do you have some MSP430 launchpads? If yes then consider building simple scope project. Don’t expect high sampling rates or accuracies but for some purposes it can be useful. Project is split into two parts – one hardware where MSP430F5528 microcontroller reads signals via ADC channel and sends it to PC via built in USB.
Another part is a computer application. It is programmed to accept data stream from board and display graphs. And finally it is worth mention that scope sample rate reaches almost 400Hz which isn’t much. This is enough many slow signal inspections like biomedical or some mechanical sensors. But hey, you get reliable stream of 16 bit samples on screen.