It is possible to have a custom object as a landing page for a Salesforce App, check the link for details:https://success.salesforce.com/answers?id=90630000000gjZNAAY
Hey if u wana use custom object in vf pages for that u have to write down the apex class first and after that u can call that apex classes in vf pages where in statndard object u can directly call that class in vf page ... Thank You
Thank You