Swackett is an outstanding iPhone weather app, and Peepometer from the same company is a top notch iPad weather app. Flashometer is a new iPhone app from the same company that combines Swackett, Peepometer, and a Flashlight app into one. Flashometer provides the 1950s style mechanical gauge based interface of Peepometer, with the classic Swackett peeps that show you what to wear based on the weather conditions.
The weather information includes current temperature, humidity, wind speed, chance of precipitation, sun times, and more. There are three different tabs with flashlight battery meter, peeps view, and five day forecast dial. The Flashlight is instant on when you launch the app, and it can be activated on any of the tabs.
Flashometer (Free, iPhone) combines a flashlight and weather app into one with a great design, and the basic info you need.