Open multiple instances of an app (spark e-mail app) I would like to use an app multiple times. I installed Spark which is from my point of view a great email app. I have two companies with various accounts (pr@...,contact@...) and instead of having all of them in the same app I'd like to have spark1.app for company1 and the same for company2/spark2.app for example.

I already tried open -n -a APPNAME but Spark is telling me that there already is a copy running !

Any suggestions ?
Even if you get two copies running, they're both going to be sharing the same set of prefs &amp; repositories... &amp; both trying to write to them at the same time. 

This is a very bad idea. 

If you want two mail apps handling two different mail accounts simultaneously, use two different mail apps.