I think it's Open CPN, but I couldn't be bothered to investigate. I've seen SeaClear for sale on eBay previously.
Well I knew this couldn't be anything worth having. I just hope this isn't a sailor who is trying to lure people into parting with cash to download rubbish charts. Could be dangerous if you thought it was uptodate for navigational purposes.
I've just downloaded Open CPN and it seems great.
It should read your cm93 charts. Just click on toolbox then select charts. Scroll to find cm93 click on it and click button to add selection.
if you use a wheel mouse go to toolbox then etc and click the gui wheel mouse box.
To get depths displayed go to vector charts and click soundings.
Tracks can be saved to disc and routes can be activated by right click
brilliant in my opinion