Hi @klakdawala and thanks for reaching out today.
We don’t have any Export to APK for now but I’ll add this request to our internal tracker so we can discuss it with the team. As always, if others would like to see this, please let us know.
About opening and collapsing sections of a page: this is not something you can achieve in our little tool which has low interactivity on purpose, as detailed here.
That being said, the Linking feature will allow you to link two mockups together if needed, so creating one mockup for each state you want to demonstrate will help to achieve your need.
Please let us know if you need anything else, we’re here to help!