This is a thumbview template for page list block by Soh Tanaka
How it works:
Step 1: Login to your website and navigate to dashboard->pages and themes
Step 2: At the bottom choose attribute page type image/file and click "Go"
Step 3: Enter 'page_thumbnail' within handle and a custom name
Step 4: Optionally click the check boxes to make it searchable
Step 5: Click on "Add Attribute"
Step 6: Navigate to your dashboard-> sitemap
Step 7: Click on a page you want to assign a thumbnail and then on properties->custom attributes
Step 8: Choose the named attribute from step 3 and choose a thumbnail from the filemanager
Step 9: Add a page list block to any page
Step 10: While in edit mode, click on the page list block, select custom template and choose 'Thumbview'
That's it, the pages with assigned thumbnail should get displayed.