Flexcil 2 is primarily used for notetaking and as a PDF reader. Combining these functions allows you to view the PDF while dragging elements from it to your notes at the same time and organizing them easily.

If you are looking for a note-taking app that allows you to do in-depth PDF annotation and allows you to do professional literature research, then you should look at MarginNote 3 as a better alternative than Flexcil 2.