Childhood skull deformities have significantly increased since the 1992 American Academy of Pediatrics recommendation to switch infants to the focal supine sleeping position to help counteract sudden infant death syndrome (SIDS). Various methods for measuring such skull deformities (caliper measurement, 3D-photogrammetry, plagiocephalometry, ultrasound measurement, laser scanners, etc.) are applied internationally. Additionally, different measurement indices and standard values are used for diagnostics worldwide. We have developed a software that can be used as an international measuring method and data collection tool in the future. The development of the mobile Craniometer-App, aims to enable parents, specialists, doctors, midwives and physiotherapists to detect, classify and diagnose infantile skull deformities with a simple digital tool. Caliper measurement and 3D-photogrammetry are regarded as the standard measurement methods for infant skull deformities at the Department for Oral and Maxillofacial Surgery of Justus-Liebig-University in Giessen, Germany. The Craniometer-App was tested on a patient group of 54 infants between the ages of 4 to 8 months, comparing its applicability in comparison to the regularly-used caliper measurements and 3D-photogrammetry. The newly generated parameter (Diag_Ratio) should represent the relation of the cranial diagonals in a simple form and evaluate the severity of cranial deformity. Despite some observed measurement deviations in comparison of the indices of the various measurement methods, which can be attributed to different levels and measurement points of the skull, our result indicates that the Craniometer-App can be used as a reliable method for measuring cranial deformities. Further investigations, improvements and clarifications are still pending for an international establishment.