Square or similar mobile card processing

I am very tired of punching in card #'s all night long for delivery orders and paying crazy fees.
I was thinking about getting a square reader for each driver but I have some questions.
Do you provide the cell phone or use the drivers phone?
Can the driver edit the transaction (add tip) after he leaves customers house?

I have cellular cc units for all of my drivers, we swipe all cards. All in, my rate is 2.36%.

I use it (3years now) and would recommend it.
The drivers use their own phones I provide cases.
Tipping involves a seperate screen so the customer would have to hit No tip button.
Since most of my employees have a newer iphone the lightning adapter is kind of annoying but they have a solution for that now.
Not having to key in transaction makes it worth it