When "friends" split a check, advice needed on getting them to fair share

[Onamuji]

I have an app on my cell phone that cleverly splits a check fairly down to % of tax and tip.

I use it for fun sometimes. Never when dining out.

I inevitably chip in for more than I have consumed when we split the check.

And I do so gladly.

I earn enough money that it's not harmful to me and life is better when you don't worry over a few bucks here and there. Especially among friends.

Don't sweat the small stuff.