It's still a constant source of annoyance for me that one of the companies I do work for insist on me signing off jobs using an iPad (no other platform available).
It's a shit app tbh, but it's just horrible having to pull out that midsized slab of junk when you can do the same job (and add far more information) with the phone in your pocket via email....or the laptop you already have online for the job.
"Why take only two devices to the job, when we can make you take three?"
My old dear loves hers though, but she's a complete couch potato. (Facebook, Words With Friends etc.)
Sounds like a rant..which it is bit.
But...for productivity: shit, for social stuff: excellent.