Background: To lower barriers to developmental screening, we designed Baby CROINC (CROwd INtelligence Curation), a digital platform to help parents track and assess their children's development through crowd wisdom. Objectives: To understand users' experiences using Baby CROINC in relation to users' technological competence and attitudes, while considering the influence of their children's presented developmental evaluations and parents' actual use of the system. Methods: Mothers of 260 children (M age= 17.6 months, SD=13.7) used Baby CROINC for two weeks. They entered developmental milestones on their children's developmental diary timeline and received statistical developmental percentile reports. Mothers then completed Usability and Technology Profile Questionnaires. Results: Mothers' experiences of the Baby CROINC system usability were associated with their attitudes toward solving technological problems, mediated by frequency of engagement in Internet activities. Mothers with a proactive approach toward solving technology problems, engage in a wide range of Internet activities, and/or view the Internet as integral to their lives had a better experience with Baby CROINC than mothers who did not. The system's perceived usability was not associated with the crowd-based child developmental percentiles or quantity of mothers' usage of the system. Conclusions: Parent's user experiences correlate with their technology competence and problem solving attitude but is not correlated with their child's developmental status. Developmental screening platforms need to solve the tension between requiring active engagement and encouraging proactive parenting.