Comparing Date Book, Datebook+, and DateBk4DateBk4’s Extra FeaturesMenu iconSplit display and time informationButtons and their viewsButtons unique to DateBk4Why the Designs of Date Book, Datebook+, and DateBk4 DifferWho is the user?The 80/20 RuleDate Book: The Most Important Aspects of an ApplicationDate Book tasks and timesHow the 80/20 rule was implemented within Date Book’s designDatebook+: The Most Important Aspects of an ApplicationThe “p” for P.M.Extra calendar viewsDatebook+ tasks and timesHow the 80/20 rule was implemented within Datebook+’s designDateBk4: The Most Important Aspects of an ApplicationDateBk4 tasks and timesHow the 80/20 rule was implemented within DateBk4’s designWhat Should Be Sacrificed?DateBk4’s pop-up common task listThe split displayButton action and common activityAbbreviating button names—hitting the screen-size wallButtons that don’t look like buttonsPreference dialog boxesWho Is Your User?