In this paper, we report on recent progress toward the development of a plug and play on-chip cytometer based on light scattering. By developing a device that does not depend on the critical alignment and cumbersome handling of fragile optical fibers, we approach a device that is suitable for non-expert users and Point-Of-Care (POC) applications. It has been demonstrated that this device is capable of detecting and counting particles down to 1 μm at 100 particles per second. This device only depends on a single microfluidic channel. Hence, the device is easy to implement, or to use on its own.