Objective To systematically review mobile applications currently available to patients to support outpatient medication self-management. Methods Three online stores were searched in March 2013 using nine distinct search terms. Applications were selected if they supported general outpatient medication self-management for adults; they were excluded if they focused on only one medication or condition, provided only a medication list or reference, only ordered refills, were written in a non-English language, or were for local pharmacy/hospital patients only. A multi-step review process was utilized by two independent reviewers to identify eligible applications. A standardized form was used to abstract data. User reviews were compiled from a subsample of applications and qualitatively coded to identify common criticisms. Results 14 893 applications were initially identified. After the multi-step review process, 424 applications were deemed eligible for inclusion by reviewers (kappa=0.85). On average, applications were rated 2.8 stars (out of 5) from 107 reviews. Almost all provided medication reminders (91.0%), half enabled patients to create a medication history or log (51.5%), and 22% could email the log to a third party. Few helped patients organize their regimen (6.2%), check for drug interactions (2.8%), or identify pills (4.0%). User reviews (N=1091) from the subsample of 26 applications revealed common criticisms, including technical malfunctions, poor compatibility with certain medications, and absence of desired features. Conclusions Hundreds of applications exist in the marketplace to support medication self-management. However, their quality, content, and functionality are highly variable. Research is needed to determine optimal capabilities, evaluate utility, and determine clinical benefit.