Once set up, Aladdinpro will automatically remind you when something expires. You do not have to open the application. Since it is a cloud based app, you don't have to worry about data being lost as well.
A record has two states. One is when it is due for renewal not in the near future (usually 60 days - that's when it is marked 'Expiring' in blue. When it is due for renewal in the near future (usually 10 days) it is marked 'Critical' and is shown in amber.