Mobile App for PMP preparation

I was looking for a app to study for PMP certifcation for my mobile devices. As I am an apple fan so I have Iphone and ipad with me. There are penalty of PMP study material on the Appstore but I found "PMP Resource (Rise up)" very usefull. It covers all the areas and process groups and defines ITTO. It has Formula calculators and PMP glossary dictionary for quick reference. The flash card cocept is fantastic as it also challenge you to remember. The exam questions for each group/knowledge area are good for reviewing and clearing concept for that area. The best part is it's under $10

Will appreciate if anyone else can share Mobile applications which can be use to study on the go....