My problem is I just want to preview a Lightning component in the developer console. There are a ton of ways to make lightning components in all sorts of other mediums, but I just want to click preview and see it. I believe I need to have a "dummy" lightning app to host it. An outline of what I have now is for the Component called "testApp.cmp"
<aura:component implements="force:appHostable">
////code
<h1>hello world, please display this</h1>
</aura:component>
and the Lightning App called "testApp.app":
<aura:application access="GLOBAL" extends="ltng:outApp">
<aura:dependency resource="c.testApp"/>
</aura:application>