Bunch: Run app only if not already running

When using the Bunch app, the example file says:

/* Apps launched by a Bunch are quit when the Bunch is closed
   Add a percent symbol to ignore it when closing the Bunch
   (i.e. keep it running) */
# %Terminal

How do I only run the application if it’s not already running?

Also, how do I avoid the audio feedback och which bunch was loaded from the Bunch menu?