I suggest incremental payments and a deposit for any work of any size (which this definitely counts of). We do 20% upfront, 50% on adhoc reasonably functional demo, and 30% before uploading to apple/releasing code.
My company's iPhone fixed fee contracts state that you surrender all rights to the work after a (long) term of non-payment and still owe the amount due so things just like this can be done when people just disappear off the face of the earth but yet salaries and contractors and artists still need to be paid for all that time.
My company's iPhone fixed fee contracts state that you surrender all rights to the work after a (long) term of non-payment and still owe the amount due so things just like this can be done when people just disappear off the face of the earth but yet salaries and contractors and artists still need to be paid for all that time.