I have been a fan of Parentlink with CCSD. As a parent I have been able to keep on top of my kids assignments and get direct messages from their teachers. I get an email every time grades are updated too.
You can always make your older student download it to their phone to stay responsible. If there was an improvement suggestion for CCSD in using ParentLink it would be to have a login for the students over age 12 so they can take on some responsibility to monitor their own progress. My 14 year old logs into ParentLink and has to tell me what is happening with every assignment for every class before he gets his weekend privileges or allowance.
Plus if you do not have a mobile phone there is always the main website: Parentlink.CCSD.Net
If you do not have regular access to the internet there is always the hotline to call.