As part of our never ending series of features designed to help you find terrific free iOS apps, we’ve found four more apps that were previously paid that have now gone free for a limited amount of time. This week we’re bringing you apps that will help you transfer and manage documents to and from your iOS device, plan meticulous workouts and exercises, superimpose multiple photos on one another, and record great looking movies from your phone or tablet. These are paid iPhone and iPad apps that have been made available for free for a limited time by their developers. There is no way to tell how long they will be free. These sales could end an hour from now or