“It’s actually a very decent intro to pump basics an gives you easy conversions for units. I like having a quick refresher to incompressible turbo-machinery in my pocket. A must have for any Mechanical Engineer that only rarely deals with pump dynamics. Cons: the UI is a bit bland, although the maker was focusing more on content. Pictures/diagrams would be nice. The cutoff for the bottom of the page is a too high, forcing you to rubberband up a 1/2″ to read the last line or so – no biggie. Overall, worth it.”