How funny that I just came across this recipe just seconds before I read your post. This looks good!

CRAB-APPLE HOT PEPPER JELLY
2 pounds crab apples (1 kg.)
1-1/2 cups water
red wine vinegar
3-3/4 cups granulated sugar
1 cup sweet green peppers
1/3 cup hot peppers

Crab apple pectin gives a good set to this hot pepper jelly. Mix and match hot peppers for colour and degree of heat. Banana peppers range

When chopping hot peppers, wear gloves and don't touch your face or eyes.

In Dutch oven, combine apples with water. Cover and bring slowly to simmer; cook until apples are very soft. Pour into colander lined with square of dampened muslin and placed over deep bowl. Weight down with saucer and heavy can. Let stand until dripping stops. Discard pulp.

Pour collected juice into liquid measure; add enough vinegar to make 3 cups. Combine in saucepan with sugar. Bring to boil, stirring. Add peppers; boil briskly for 8-10 minutes or until set. Stir for 7 minutes to prevent floating peppers.

Pour jelly into hot, sterilized 8-oz sterilized preserving jars. Seal with two-piece canning lids. Let cool and refrigerate. For long-term unrefrigerated storage, process in boiling-water bath for 5 minutes immediately after sealing jars.

Makes six (8 oz.) jars.

Here's one you might try. It's like the ones from the grocery.

SPICED CRAB APPLES

Crab Apples, washed with stems intact
3 Cups Water
3 Cups Sugar
1 Cup Red Wine Vinegar
1 Cup Red Hot Cinnamon Candies
1 Cinnamon Stick
1 Teaspoon Whole Cloves
1 Teaspoon Red Food Coloring, optional

Pack Crab Apples as tightly as possible into a half gallon jar. Put all remaining ingredients into a heavy bottom sauce pan and over medium heat, stir until the Candies are dissolved. Bring the mixture just to a boil.

Pour the boiling Juice over the Crab Apples until completely covered and cap tightly. Cool on the counter and store in the refrigerator as the jar may not seal.

This recipe can be doubled or tripled as necessary.

Steve

Oh, I just made some pickled spiced crabapples yesterday and some jelly, too.
Here is a link to the recipe I prefer :
There is another one on the site, but they are a lot softer. Not nearly as nice. I also put Pickle Crisp in the jars to see how it affected them.

Here is a link that might be useful: spiced crabapples

My favorite way to use crabapples is to make Crabapple butter, it's spicy with cinnamon, a bit tart from the crabapples, we like it as a condiment with all kinds of things especially ham!

Crabapple Butter
6 cups (1.5 L) sieved crabapple pulp
Grated peel and juice of 1 orange Optional
2 cups (500 mL) sugar (for every 1 cup of pulp, add approximately � cup of sugar or to taste)
1 tsp (5 mL) cinnamon, optional (sometimes I put in a cinnamon stick or 2 and remove them before processing)
50 to 60 cinnamon red hots

Pick crabapples, add water (about � the volume of the crabapples) simmer on medium until apples are soft.

Combine pulp with orange peel and juice in a Dutch oven.
Place over high heat and bring to a boil, stirring constantly.
Reduce heat to medium and boil gently, stirring frequently to prevent scorching, until mixture thickens to desired consistency.
Stir in sugar and spices, if desired, and return mixture to a boil, stirring constantly.
Ladle into hot sterilized half-pint (250 mL) jars, leaving ü inch (6 mm) headspace.
Remove air bubbles with a narrow rubber spatula or plastic knife.
Add additional crabapple butter, if necessary, to maintain headspace.
Wipe jar rims thoroughly with a clean damp cloth.
Seal and process in a boiling water bath. Process for 15 minutes

You can use them to make a pectin and mix them with all sorts of other fruits, since they are so full of pectin. I think if you find recipes with quince or even apples or cranberries, cripples might be a nice substitute.
I wish I had a crabapple tree. My parents had an ornamental one when I was a kid but the apples would have still been good for canning.

My absolute favorite apple jelly is made with the juice from crabapples. It really tastes like it is supposed to. And because the pulp is so flavorful, after I got the juice out for jelly, I've even taken the pulp and run it through my seive to get rid of seeds, skins, and stems, and then made a kind of apple butter that turned out very good.