应用程序通过预定义的频率改变手机的壁纸（背景）
How to configure backgrounds changing:
1. Please, be sure that Internet connection has been established on your device;
2. Launch the application;
3. Slide for fancy picture. This picture will be set up as a first wallpaper in your device.
4. Select convenient wallpaper chaning frequency;
5. Apply your configurations. Now application can be wrapped.
For correct application execution please connect your device to the Inernet connection sometimes.Application should have an ability to download new backgrounds from the server.
If there is no more that one picture is uploaded to the device then after timer is off the wallpaper won't change. Timer is going to be reset.