Weather Icons
The icon designs are originally by Lukas Bischoff. Icons are based on the 123 Weather Icons Project Font. The font is developed by Erik Flowers. Weather Icons are licensed under SIL OFL 1.1.
Weather Information
Weather information is provided by openweathermap.org.
Charts
For charts AChartEngine is used. AChartEngine is an open-source framework, free to use in any free or commercial application. AChartEngine is contributed based on the Apache 2.0 license.