K2 designer will create forms and views that can then be used in the K2 mobile app, K2 studio can create workflows that present user tasks/client events to the user via the K2 mobile app, there are no special creation tools for K2 to leverage the use the the K2 mobile app.  Just follow the documentation on help.k2.com as there are some special configuration settings to enable the K2 mobile app to work as intended ( http://help.k2.com/onlinehelp/k2blackpearl/userguide/4.7/default.htm#4.use/k2_mobile.htm )

Thank you,

Ted