iOS apps leaked more user data than Android apps, but of the more benign kind
On average, Android apps that passed through the company's cloud transaction, leaked user data in 0.3% of the cases, while that figure was 0.5% for iOS apps, yet the number there is derived from a larger sample. Both are not big numbers, though, plus it is mostly device info and location data that are shared.
Only a fraction of the leaked data was found to be personally identifiable info (PII). This is where Android and iOS differ again - just 0.2% of the iOS leaks included PII data, while on Android that share was 3%. The geographic distribution of the leaky apps is also pretty interesting - 70% of iOS privacy-related traffic comes from China, while for Android it's from US and UK. Not very surprising, given the come-and-go state of Google Services on Android phones in China.