Objective: To identify smartphone menstrual cycle tracking applications (apps) and evaluate their accuracy, features, and functionality.
Methods: In this systematic evaluation, we searched the Apple iTunes store for free menstrual cycle tracking apps for patient use. We considered an application accurate if menstrual cycle predictions were based on average cycle lengths of at least three previous cycles, ovulation (when included) was predicted at 13-15 days before the start of the next cycle, and the application contained no misinformation. We modified the APPLICATIONS Scoring System to evaluate the features and functionality of accurate apps.
Results: Our search criteria yielded 1,116 apps; 108 remained after excluding duplicate, non-English, nonmenstrual cycle tracking, and priced apps. We further eliminated 88 that did not meet inclusion or accuracy criteria. Of the 20 accurate, free apps, 80% contained information for conception and 50% for contraception. Common features and functionality included password protection (55%); no requirement for Internet connectivity (80%); no advertisements (65%); in-application technical support (70%); medical disclaimers (65%); health education (55%); tracking of menstrual flow (70%), symptoms (70%), and intercourse (75%); alerts for next menses (65%) and fertility (55%); and cycle length information (75%). Forty percent were available for Android. Usefulness for fertility medications (15%), professional involvement (5%), and cited literature (5%) were rare.
Conclusion: Most free smartphone menstrual cycle tracking apps for patient use are inaccurate. Few cite medical literature or health professional involvement. We list accurate apps to aid health care providers in understanding the key components they can use to evaluate and recommend apps for patients.