Works on iOS 7, 8, and 9. Has arm64 support.
Forecast for iOS 7/8/9 adds current weather details (temperature, condition, highs and lows for the day) to your lock screen.
Swipe to the right or tap the lock screen weather details to show the full forecast on a separate lock screen page.
Forecast also can show animated lock screen and home screen wallpapers showing the current weather conditions for either your current location or your first configured location in the iOS weather app.
All features are configurable through the Forecast preference pane in the Settings app.