If it's the newer Cricut without the separate dies, use it for applique. I wouldn't cut a lot of blocks with them, some do.
All of the companies make an iron-on for fabric. I use the brand at first just to test the iron-on. If there is no difference, then will use a more traditional one made by Steam a Seam, etc.
You can test applique sizes before using by cutting paper and adjust size electronically in the cutter's software.
Have fun with it.