I've been using Trowl for a while, but not with Growl, rather I prefer
Snarl:
https://sites.google.com/site/snarlapp/home
It works perfectly with Snarl, but is a bit of a pain having to hit
the continue button after every reboot, when all I want is for the app
to auto-start and not bug me about Growl.
Thanks for listening :-)