Secondary
Faith at home includes Collective Worship resources for secondary and primary schools. See there resources here
https://www.archbishopofyorkyouthtrust.co.uk/yla-free-resources Archbishop of York Youth Trust do free KS3 resources
http://www.creativeproverbs.com/ is a searchable site for proverbs/thoughts for the day around the world.
http://www.oxfam.org.uk/education/resources/ has resources for assemblies about third world and social justice issues.
http://learn.christianaid.org.uk/TeachersResources/secondary/ResourceOvervie w/assembly.aspx for ready to use secondary assemblies;
Youth for Christ
Youth for Christ (YFC) have great resources that can be used and adapted for schools for young people to explore spirituality. Find them here
https://www.cdbe.org.uk/support-for-schools/resources/collective-worship-resources
On this page you will find the secondary school collective worship resources to help educate your pupils about modern slavery -
https://www.modernslaveryeducation.com/senior-collective-worship
Designed particularly for affiliated secondary schools, there are ideas on this site for using a quotation as a starting point with suggestions for follow up questions -
Here you can find many ideas, and assemblies with a dedicated secondary section that can be used and adapted for collective worship -
https://www.assemblies.org.uk/about/links/