trigger UpdateChildAccount on Account (after update)
{
	AccountHandler handler = new AccountHandler();
	if(Trigger.isAfter )
	{
		if(Trigger.isUpdate)
		{
			handler.doAfterUpdate( trigger.new ,trigger.old , trigger.newMap , trigger.oldMap)
		}
	}
}

public class AccountHandler 
{

public void doAfterUpdate(List<Account> lstNewAccount,List<Account> listOldAccount,Map<Id,Account> newAccountMap ,Map<Id,Account> oldAccountMap )
{
	List<account> accountsBeingSaved = [SELECT id, name, parentId FROM Account WHERE parentid IN :lstNewAccount]; 
	List<account> childAccountsToUpdate = new List<Account>(); 
	for(Account a: lstNewAccount)
	{
		for(account ac:accountsBeingSaved) //loop through first list of all accounts being saved and call it 'ac'
		{ 
		if(ac.parentid == a.id) //'ac' is a child and 'a' is the parent
		{
			//add this child account to our List
			childAccountsToUpdate.add(new Account(Id=ac.Id,OwnerId=a.OwnerId,Approval_Progress__c=a.Approval_Progress__c,Status__c=a.Status__c)); 
		} 
		}
	}
	if (childAccountsToUpdate.size() > 0)
	{ 
		try 
		{
			update childAccountsToUpdate; //update the child accounts
		} 
		catch(DmlException e) 
		{ 
			//catch exceptions in system.debug
			System.debug('An unexpected error has occurred: ' + e.getMessage());
		}
	}
}

public void doBeforeUpdate( List<Account> lstNewAccount,List<Account> listOldAccount,Map<Id,Account> newAccountMap ,Map<Id,Account> oldAccountMap )
{
	
}
}