I enjoy making fruit leather out of applesauce and the different flavored apple sauces made by Motts, Roundys, and some others. The variety of flavors is very limited though. So I tried mixing some different flavors of Crystal Light with the regular applesauce. They tasted great. I mixed one of the 16 ox packets with two of the individual serving applesauce cups. I put 4 of the cups on one tray in the dehydrator and run it for about 15 hours. Great snack.

My wife used to add differnet flavors of Jello to the applesauce to make fruit leathers for my son.

I tried the jello idea last year, but the leather stayed too soft and sticky, but it did taste good.

Flavor pouches are a good idea may have to try that also.
You can also grind up fruit with a food processor or blender and mix it with apple sauce to get different flavors. I have cherry and blueberry finished right now and put in strawberry yesterday and peach this morning. My wife fav is the cherry but I didnt think it was very cherryie, not bad just not as cherry as I was hoping. It also stayed sticky alot longer than the others have (dried for 20 some hours still sticky). The Blueberry is great and so is the strawberry. The peach is an experiment, we will see how it turns out tommorow.
The mixing ratios you can just fiddle with. Ive had strawberry apple that was barely pink to use up leftover berries from somthing else and ones that were 75% strawberry. I use frozen fruit of various types (when an option) to add because I am lazy. I like not having to clean, pluck leaves, peel, or pit.