The thing is that Splitwise is just a ledger, it doesn’t have any actual mechanism for transferring money (or didn’t last I used it, a few years ago). The nice thing about that is that you can settle up however you like. I’ve known people who track shared expenses (splitting lunch, etc) in Splitwise and settle up using Venmo, but you could also use cash.
The other way to do it is to just never settle up - if you have a group that often goes out to lunch together, just track it in Splitwise and the person with the lowest balance always buys for everyone.
