From GameBrew - a wiki dedicated to Video Game Homebrew.
Slides is an application for viewing photos.
Download and extract file.
Copy the .nds to the root of memory card.
Create a directory sliDeSImage to the root of memory card.
Resize images to view it in 256 * 192 or 192 * 144.
Copy images resized in the directory sliDeSImage.
It provides two modes for photo viewing: Manual mode and Automatic Slideshow mode.
You can set Timing to select the time of displaying a photo, four lengths are available, 5s, 10s, 30s and 60s.
Can control with Stylus.
R - Next image
L or B - Previous image
X - Activate slideshow
Y - Disable slideshow (back to Manuel)
D-Pad - Set timings
The application was tested on M3SImply linkers, and Cyclo DS Evolution M3Real.