A common complaint among cancer patients is that symptoms like fatigue and insomnia persist long after treatment has ended. The first ResearchKit app to address this is called "Share the Journey," for breast cancer survivors. By downloading it, women join a clinical study that "aims to understand the symptoms after breast cancer treatment, why these symptoms vary over time, and what can be done to improve them," say the creators. The app logs activity, sleep, and mood patterns along with info about the user's cancer history.
Men can't participate in this study, though future ResearchKit apps could address prostate and other cancers. (In the meantime, check out another helpful app for cancer patients, Pocket Cancer Care Guide).