I read a lot of pdfs for study and I write notes for them. I read my pdfs on a tablet and I currently write notes with Moon Reader. But I can't export the notes and highlights from Android to Windows/Linux. What program(s)/app(s) can I use to be able to export/import notes?
Xodo is completely free, and available on Android/iOS/Windows Desktop/Windows Mobile. You can share a document with your self, and it will be available on all devices, and even in a web browser (no installation required).
There is no import/export, because there is no need when sharing.
To get started sharing see Xodo Connect option here. http://feedback.xodo.com/knowledgebase/articles/614835-getting-started-xodo-basics