here is very simple applescript to do that through ical.
tell application "application name"
activate
end tell
open applescript - script editor to write that script, then in ical set an appointment to repeat everyday, under the alarm option tell it to run script and select the applescript you have made.
to close it, write another applescript that says
tell application "application name"
quit
end tell
set another appointment in ical and set that script to it.