This isn't just a trail camera viewer. It is a complete SD/MicroSD/TransFlash read/write slot for PC USB, Android, and Apple iPad/iPhone Lightning ports. Of course it works excellently for its originally stated purpose if you don't want to do anything else with it!
For Android or a PC you plug it in and use whatever software you prefer to browse the card and view/work with files. Android and popular computer operating systems will prompt you or open a program for you.
For iOS, since Apple doesn't believe in standardized filesystem access, you plug it in to your iPad or iPhone and iOS will prompt you to install an app called "i-FlashDevice". The app works well, is intuitive, and surprisingly powerful, acting quite effectively as a file manager, media player, etc. It even allows you to backup your iPad/iPhone stuff to the card or use your iPad/iPhone camera or microphone to save directly to the card.
This means my iPad is no longer limited to the small amount of memory that Apple thought I should have. I can keep a large library of movies, TV shows, music, or whatever on one or many cards to carry around with me and play wherever I may be, regardless of whether or not internet is available.