I am doing a test chrome sender app for ChromeCast based on this. This is a simple app which plays a photo slideshow from playlist (in a loop).
How can I make it to continue playing even after I closed sender app?
Pretty much the way youtube video keeps playing on your TV via chromecast even after you close youtube app used to start playing the video.
Or maybe, I also need a custom receiver app which would accept the list and keep looping it?
Where are the images coming from? In order to not have dependency on the sender, images need to be available somewhere in the cloud, or at least on a server that will remain available independently of the sender. In addition, you need to write a custom receiver so you can pass the list of images (urls) to it and your receiver should have the logic to loop through them one by one, possibly add some transition effects, etc.