There are many crock pot applesauce versions out there, but this one is my fave and comes from www.allaboutfoodstorage.com:
SLOW COOKER APPLESAUCE
4 lbs. tart apples, cored and thinly sliced (about 12 cups)
1/2 cup sugar (I used about 1/4 c.)
1/2 tsp. cinnamon or apple pie spice
1 cup water
1 Tbsp. lemon juice
Mix apples with cinnamon and sugar and put into Crock Pot. Pour water and lemon juice over the apple mixture. Cook on low for 6 hours, or on high for 3 hours.
If you cook it longer (8-9 hours on low) and stir it a bit, you'll get apple butter, and if you cook it as described in the recipe above, you'll get chunky applesauce. With a picky little boy in my house, I cook for 7 hours on low, then mash a bit (with my potato masher!) to get a creamier version.
In the past I've also used Splenda brown sugar (in place of the granulated sugar) just to mix it up, and once when we bought very sweet apples, I used a scant half-cup of sugar for a huge batch of applesauce. It tasted great with very little extra sweetener!
Once I made pear sauce because I had too many pears, and it lost all the grainy pear texture and everyone thought it was dark apple sauce. This is a truly versatile recipe and freezes/cans well.