Smartphone apps can potentially help in enhancing oral anticancer medication (OAM) adherence. Patient adoption and efficacy of such apps depends on inclusion of user-centred and evidence-based features. The objective of this study was to identify important design considerations from the perspectives of patients taking OAMs, caregivers and oncology pharmacists. The study employed a qualitative study design. Data were collected using in-depth interviews with patients (n = 15), caregivers (n = 3) and pharmacists (n = 16). Interviews were audio-recorded, transcribed verbatim and inductive thematic analysis approach was used in data analysis. Monitoring medication-related problems, medication information, replacement of or integration with current systems and accessibility of app content on devices other than smartphones were the key themes identified in the analysis. Flexible input methods for monitored data, glanceability of monitored reports/information, near real-time adherence enhancing and symptom management interventions and customisable reminder options were design considerations identified under the monitoring medication-related problems theme. Participants suggested the provision of focused and easily understandable medication information with a potential for personalisation. Integration of app-based adherence systems with patients' electronic medical records with added mechanisms for alerts in the dispensing system was also suggested as a key design requirement to improve quality of patient care and facilitate adoption by clinicians. Finally, smartphones were the most favoured platform with optional accessibility of app content on other devices. In conclusion, important design considerations were identified through a user-centred design approach. The findings will help developers and clinicians in the design of new app-based systems and evaluation of existing ones.