The Activity system displays progress information during system & user initialisation. One aspect is the provision of splash screens. The minimum user screen size permitted is 1024x768. The library system provides a tiled background to cater for larger screens. The top 1024x640 of the splash area is for the Activity to display informational images during the initialisation process, the size is fixed and the image must also be a JPEG(JPG) image. The library uses the remaining 1024x128 to display progress information. See example.
Inside the Custom/Splash directory you may place as many images as you wish, one must start with the string "Initial" (eg Initial.jpg, Initial_Splash.jpg etc) this is the image that will be displayed first up. The display of subsequent images is by sorting on the file name, if you have a preference name the images something like i01.jpg, i02.jpg, i03.jpg and so on and they will be displayed in that sequence. If there are not enough images the start up code will recycle the list but not the initial screen.
Do not include important information in splash screens. There is no guarantee as to how long they will be displayed or if they will be displayed at all. They are simply displays like you sometimes see in installation programs as this are being done.