I used to have a PC that runs, IBM Lotus Organizer. I changed to a Mac and I need advice on what similar organizer like Lotus I can use for my MAC.
On the Mac Operating system there is a native calendar app called iCal Click on the iCal Icon on your Dock to run the application.
You can add/setup your ICloud, CalDAV,Exchange or add other calendars to iCal.
You can share it to your apple devices as well to sync your calendars automatically.
When you change an event in your phone all your devices will update automatically as well for more information here is the official iCal support from apple
