iPhone exposure meter apps Cine Meter and Cine Meter II have been updated for proper operation with iOS9. If you use one or the other, please update as soon as possible. Cine Meter’s new version is 1.6; Cine Meter II is now at version 1.9.
iOS 9 changes the way brightness is reported on some iDevices, breaking exposure metering on older versions of Cine Meter and Cine Meter II. The new versions default to using “computed brightness” on iOS 9 instead of relying on brightness metadata. However, some devices appear to report proper metadata on iOS 9, and you can switch “Use Computed Brightness” off if your iDevice is one of the lucky ones.
Disclosure: I’m the creator of Cine Meter & Cine Meter II, so you’d better believe I have a biased interest in reporting this story!