I like heat n bond. Here is a good video to see what the different weights are like and help you to pick what to use.
Heat n bond lite and feather lite
Also, if you need to move your applique and there is adhesive left on the fabric, get a piece of aluminum foil and place it shiny side down on the adhesive and iron the foil. You may need to do this a few times, always using a clean piece of the foil so you don't redeposit the adhesive that did come up on the foil. Removes the adhesive like a charm!