Yes! As long as a pack has been added to “My Packs”, you can switch between the packs listed there.
To add a pack to “My Packs”, just tap on the “Discover” icon at the bottom of your screen. From here, scroll around and tap on the pack you would like to access. Once the pack description appears, you can select “+ ADD TO MY PACKS”.
Once added, return to the “Home” screen and the pack should appear under “My Packs.”
You can then switch between the content as you desire, and the progress bar will indicate how far along you are in completing the whole pack.
Minis, Singles, and Kids content can be accessed at any time.