There is no limit that is enforced by the app. The app runs all of the inputs within a single process using multiple threads and is thus very efficient. There is no way to realistically derive a maximum number since this is dependent on a lot of factors. That said, I have tested it against a very high number of inputs and it works well. I tested the app with 600 pings per second (600 inputs pinging every second) on a low-end laptop and it worked fine.