Place the apples in a slow cooker. In a medium bowl, mix the sugar, cinnamon, cloves and salt. Pour the mixture over the apples in the slow cooker and mix well.
Cover and cook on high 1 hour.
Reduce heat to low and cook 9-10 hours, stirring occasionally, until the mixture is thickened and dark brown.
Uncover and cook on high 1 hour.
Place in refrigerator overnight.
Transfer into a food processor and pulse just until smooth.
Spoon mixture into sterile containers, cover and refrigerate or freeze.