In Lightning Experience UI, what controls what goes into the Items section in the App Launcher? I added a new Custom Object but it does not appear there. Does the Custom Object have to have a tab to show up?

Thanks

I am using data tables from https://www.lightningdesignsystem.com/components/data-tables/#site-main-content

By default the table headers are gray. I was wondering how I could change the background color of the table headers. 

When using <force:recordView />, where do I set up the type MINI or FULL? Are these page layouts in salesforce I can set up declaratively?

I am using data tables from https://www.lightningdesignsystem.com/components/data-tables/#site-main-content

By default the table headers are gray. I was wondering how I could change the background color of the table headers. 

When using <force:recordView />, where do I set up the type MINI or FULL? Are these page layouts in salesforce I can set up declaratively?