1. A data processing apparatus for a mobile terminal, the apparatus comprising: a storage unit for storing data and an integrated data processing application; a display unit for displaying data and screens of the integrated data processing application; an integrated data processing module for selecting a reference date, collecting pieces of data created at the reference date from the storage unit, and processing the collected pieces of data in an integrated manner according to preset processing conditions; and an application management module for reading the integrated data processing application from the storage unit for execution, and displaying processing results on the display unit together with associated screens of the integrated data processing application, wherein the processing conditions are at least two in number, the integrated data processing module processes pieces of data into groups of results according to each of the processing conditions, and the application management module displays the groups of results separately from each other, wherein the groups of results include a tag cloud zone and the tag cloud zone includes tag clouds which include tags that are attached to individual diary entries written by a user and listed at multiple levels according to frequencies.