Asthma is the most common childhood chronic illness. Its management requires that caregivers have access to a variety of information. For example, asthma action plans (AAP) are written instructions for responding to escalating asthma symptoms. Icons have been used to facilitate the accessibility of health information and we investigate whether they benefit parents of young children. We conducted a 4-part study with 36 participants where we (1) gathered requirements for an asthma management mHealth tool (2) assessed the comprehension of icons to be used in an AAP (3) compared the usability of a text-based (T-B) vs. icon-based (I-B) AAPs (4) and gathered feedback about an mHealth tool we designed. Results suggest that the icons we developed were highly matched to their meaning (92% translucency). Usability findings showed that in general both AAPs were equally matched. However, benefits accrued to I-BAAP users in relation to greater accuracy and speed of response in scenarios that required parents to identify asthma symptoms. Two-thirds of parents indicated that they would prefer to use the I-BAAP to manage their child’s asthma. The remaining third preferred the T-BAAP because it contained more details. We conclude with recommendation on how designers and researchers can improve mHealth tools for caregivers of asthmatic children.