This article is about running SharePoint Hosted App workflow steps with elevated permissions. Follow below steps in order to run any workflow activity with elevated permissions.
1. In AppManifest check 'Allow the app to make app-only calls to sharepoint' and add required permissions. ex: You need Web or List manage permissions to set Item level permissions in the workflow activity.
2. In Workflow Add 'AppOnlySequence' available under 'SP-Utilities'.
3. Add activity that need to execute with elevated permissions in 'AppOnlySequence'.
Now the activity added in 'AppOnlySequence' will execute with App permissions instead of user permissions.