Any of the major document signing web services. That’s one of the few of those that works just as well on a desktop or laptop—the difference is, if it’s someth

Any of the major document signing web services. That’s one of the few of those that works just as well on a desktop or laptop—the difference is, if it’s something time-sensitive and comes in while you’re, say, in the line at the grocery store, or just on the couch watching TV, you just tap-tap-tap-tap and you’re done, move on with your day, barely even interrupts whatever you’re doing. [edit] that is, the functionality’s just as good on desktop, but it’s not better, and a phone is far more convenient.