Mac OS won't let me install Jammr because it is'nt safe! (Not a verified developer)

So do I now delete it?

Frustrated newbie

Chris, Denmark

You need to simply bypass the Mac setting.

How do I trust an untrusted developer on Mac?
To bypass this restriction, select “OK” on the popup to close it, then go into the “Security & Privacy” section in your “System Preferences.” Below the Gatekeeper options in the “General” tab, you'll see the app that was blocked from opening. To trust it, select “Open Anyway” and that's it.Oct 21, 2014

Thanks