I am working on sharepoint 2013 apps. And I want my app to be on a team site. So I deployed one sample test app on a team site. On a developer site it is working fine but on a team site it is not showing the page properly. What would be the reason?
Try changing the master page.
Open the page in Google Chrome. Right click on any element and inspect in Browser Toolbar. See if you get a CSS File named oslo.css (while using oslo as master page) or Correv.css (Seattle master page)
Delete all CSS.
Check if your UI is what you expect it to be. IF yes then the UI distortion is due to your style and default SharePoint styles.