A number of medical smartphone applications have been developed to assist clinical oncology specialists. Concerns have arisen that the information provided may not be under sufficient scrutiny. This study aims to analyse the current applications available for clinical oncologists in the UK. Applications aimed specifically at physician clinical oncologists were searched for on the major smartphone operating systems: Apple iOS; Google Android; Microsoft Windows OS; and Blackberry OS. All applications were installed and analysed. The applications were scrutinised to assess the following information: cost; whether the information included was referenced; when the information was last updated; and whether they made any reference to UK guidelines. A novel rating score based on these criteria was applied to each application. Fifty applications were identified: 24 for Apple's iOS; 23 for Google's Android; 2 for Blackberry OS; and 1 for Windows OS. The categories of applications available were: drug reference; journal reference; learning; clinical calculators; decision support; guidelines; and dictionaries. Journal reference and guideline applications scored highly on our rating system. Drug reference application costs were prohibitive. Learning tools were poorly referenced and not up-to-date. Smartphones provide easy access to information. There are numerous applications devoted to oncology physicians, many of which are free and contain referenced, up-to-date data. The cost and quality of drug reference and learning applications have significant scope for improvement. A regulatory body is needed to ensure the presence of peer-reviewed, validated applications to ensure their reliability.