Not scientific or professional (and yeah, I gave it a overly fancy name, lol), but just a simple Arabic Alphabet recognition test I made up several years back so that I didn't have to keep writing out the letters to test them. (Another great option would be a set of flashcards. ;)
Then there's this nifty recording sheet so that I could test my kids throughout the year and mark which letters they had mastered or had trouble with.
