It's not hard to pay the restaurant bill with a credit card or account, but splitting the bill and settling up is another story.
There's a great article from Consumer Reports here.
Questions abound: to you tip off total before tax or after tax? Do you divide the bill by the number of people or do you allocated the bill based on orders? And then there's that vexing question of "can I just have a forkful of your dessert?"
But the tech world is ignoring those issues (best left to experts in fields such as manners and relationships) by making it easy to pay these small inter-personal transactions that show up every day.