1. No crazy gesture UI. I am not a fan of non-inuitive gesture-based UI because there are so many apps out there. People cannot remember all the gesture invented by different app. I want the app has visual cue to prompt user to touch it.
2. simiple with enough data. A lot of weather app has way too much information.
3. funcctional: I want the app has current temperature, hourly forecast and future forecast.
So this is my sketch:
basically. the user will swipe left or right to get to diferent city. the solid and hallow dots will give the user visual cue that they do swipe the screen like they do on the home screen. and the slider will allow user to look into today's hourly forecast.
* I change the dots from tops to the bottom because I think it more confroms to iPhone home screen convention. and It's less clutter on the top.
* the gear icon will allow user to add more city or other settings custimization.
This is the main screen (I use custome slider because the iOS slider style doesn't watch with my design.)
When user move the slider, the weather info will show hourly weather foreast.
When user tap on the gear icon on the upper right. The main screen will slide down to show the settings page. User an choose the Unit, different theme. Add/Delete/Modify City. (swipe to delete, tap and hold to rearrange the city. tap the last row to add a city.) To dismiss the settings page, tap the main screen.
other theme (color options)
P.S. In the world of flat design trend. I am unapologetically loving drop shadows and shadings as long as they are subtle.