If your firm allows it, you can download a copy of a revealed exhibit — for example to annotate it yourself or open it in another PDF viewer. (The host can turn off downloads for a deposition; if they have, this option won't appear.)
Once a document has been revealed, select it in the left-hand document list, then click Document Actions at the top-right of the document viewer. In the menu, choose:
Download PDF — the exhibit as a PDF (without the exhibit stamp).
Download Original — the original uploaded file in its native format.
The first time you download, you may see a brief notice; the file then downloads through your browser, where you can open it in any PDF viewer. On the tablet app, use the download icon in the header and choose which app to open the PDF in.