mighty expensive fees, its probably done by a Lubavicher, thats why you see it around there & the ohel etc.
you can get donation tablets for free from https://nedivim.org/ with your own CC processor
I spoke with Y.Kratz (which manage those things in the 770) and he told me that they had nedivim before in the 770 Shul and they took it off because the touch wasnt working properly and people were not giving through the tabs. Also he like the fact that the
ichessed kiosk is directly connected to their stripe. From what i see there the ichessed kiosk are really nice and bright compared to the nedivim ones. Also don't forget that nothing is free in life... usually when it's free your are the product...
Also imo nedivim tabs are doing 100 things, at the end people get confused if it's a donation tab or an ipad for shul.