%0 Journal Article %T Modular Mobile Application Design %A Jim Hahn %A Nathaniel Ryckman %J Code4Lib Journal %D 2012 %I Code4Lib %X This article describes the development of the Minrva library app for Android phones. The decisions to build a native application with Java and use a modular design are discussed. The application includes five modules: catalog search, in-building navigation, a barcode scanning feature, and up to date notifications of circulating technology availability. A sixth module, Amazon recommendations, that is not included in the version of the app that was released is also discussed. The article also reports on the findings of two rounds of usability testing and the plans for future development of the app. %U http://journal.code4lib.org/articles/7336