Yes, the POLYAS Online Voting Manager lets you see who has already cast their vote under the tab “Eligible voters”.
Also, you can export an extended electoral roll in Excel format after the election and see who exercised their voting rights and who did not.
Furthermore, you can view the current voter turnout status on the “Turnout / Results” tab.
Please note that voter turnout is updated every ten minutes, so there may be short delays in the display of the voter turnout.
All of these options are available from the Self-Service at no extra charge.