This is iSolveWaiting, a waiting line calculator app to get queueing theory statistics and probabilities. A waiting line system is represented by units randomly arriving and trying to be serviced by one or more resources; however a queue line (or waiting line) is going to occur if those units arrive more rapidly than the capacity of the system. Queueing theory is studied in the field of operational research and statistics and probabilities are analytically determined. Usual statistics are utilization rate of the system, length of queue, length of system, time waiting in queue, time spent in the system. There are probabilities such as the probability of how busy the system is or not, the probability of an arrival having to wait or not, etc. Those performance measures are important as issues or problems caused by queueing situations are often related to customer dissatisfaction with service or may be the root cause of economic losses in a business. Analysis of the relevant queueing models allows the cause of queueing issues to be identified and the impact of proposed changes to be assessed.This version is universal: iPad, iPhone and iPod Touch are supported.