Is it possible to create a program (either .app application or .exe server) which sits in the background and checks to see when an application is to be launched, and then performs its own action before the app launches?
E.g. the program is loaded in the background. The user then launches the built-in 'To-do' application. BEFORE the To-do application loads, my app pops up with a messagebox saying 'To-do about to be launched. Proceed Yes/No?'? It's important that my app pops up BEFORE the To-do program launches though.
Any ideas? Code samples would be even better.