Mobile Health (mHealth) applications have seen strong growth in recent years, but they are often not systematically evaluated. A Delphi survey was conducted to identify key elements for the evaluation of mHealth applications. Sixteen experts participated in the study, and the study yielded a list of 79 key elements with expert consensus. Thirty-two elements were in the category of structure quality, 29 in process quality, and 18 in outcome quality. The number of key elements highlights the complexity of conducting systematic evaluations of mHealth applications.