You can make content available to you when you are offline. To do this by clicking the little cloud icon at the top right of the window that opens when you select a meditation.

All downloaded content will remain in the same location. For example, if you have downloaded Breath and Sound from the Mindfulness Foundations program, to access it head to Explore > Adults > Mindfulness Foundations > Breath and Sound. When you have no internet connection you will only see the meditations you have available offline.