If you cannot see annotations, text, images, etc. when you open a document created in Flexcil in another app, please check the following guide.
Export to PDF for print from Flexcil
Select the document you want to move by long-pressing it in the Flexcil file manager.
Select the Share button at the top of the screen.
Select 'Flattened PDF' from the document export options and choose Export.
You can specify whether to include textboxes, images, handwriting data, and document backgrounds.