Background: Informal caregivers of older adults provide critical support for their loved ones but are subject to negative health outcomes because of burden and stress. Interventions to provide information and resources as well as social and emotional support reduce burden. Mobile apps featuring access to information, assistance with scheduling, and other features can automate support functions inexpensively and conveniently and reach a greater proportion of caregivers than otherwise possible. Objective: The aim of this study was to identify mobile apps geared towards caregivers of older adults, catalog features, and suggest best practices for adoption based on empirical findings of beneficial interventions in the caregiving literature. Methods: Search for apps focused on ones catered for caregivers of older adults in Google Play and iTunes, compiling their features, and identifying features reflecting categories of support identified in successful intervention studies to negative caregiver outcomes. Intervention research indicates that provision of information and resources, assistance in practical problem solving, coordinating care among multiple caregivers, and emotional support reduce caregiver burden. Results: Despite approximately over 200,000 mobile health–related apps, the availability of mobile apps for caregivers is relatively sparse (n=44 apps) as of October 2017. Apps generally addressed specific categories of support, including information and resources, family communication, and caregiver-recipient interactions. Few apps were comprehensive. Only 8 out of 44 (18%) had features that addressed three or more categories. Few apps provided specific stress reduction exercises for caregivers, which is important for reducing burden. Conclusions: Mobile apps have the potential to provide resources, just-in-time information for problem-solving, and stress reduction strategies for caregivers. Many apps offer functions that have been shown to reduce burden and improve health outcomes in caregivers, but few provide emotional support. Using an evidence-based practice approach, mobile apps for caregivers can provide multiple beneficial support functions. Apps can serve a much larger proportion of this highly underserved population in their mobile form than more traditional means, improving their health and quality of life.