Ratings & Reviews performance provides an overview of what users think of your app. Here are the key metrics to help you identify how your app is rated by users and how successful is your review management strategy.
User reviews affect conversion to installs and app rating. Featured and helpful reviews are the first to be noticed by users and in case of no response can affect download rate.
WP 31s is a classic RPN scientific calculator based on the powerful but more complex WP 34s. Now available on iOS too (see the support site for other emulators and for the real stuff). It is not programmable but has a rich function set for daily use and is easier to use, thanks to a less cluttered keyboard. A manual can be downloaded at http://sourceforge.net/projects/wp34s/files/doc/Manual_wp_31s_1_2q.pdf/download