Ability to change country setting
I love the Splitwise integration with Venmo, it makes settling up so much more easier. Though I had to struggle a bit to understand why I was not able to see that option on Splitwise when I moved to the US last year and installed Venmo on my phone.
Turns out, I had set up my Splitwise account back in India, and since Venmo integration is available only in the US I was not able to get the "Settle with Venmo" link on my app/web page because my country was still set to India. I had to contact Splitwise support to get it changed.
Though this may not be a frequent issue, it would be helpful to have an option to "Change Country" in Splitwise (and maybe use GPS to verify if the user is in the correct country?)

Sorry for the trouble! Yeah, our automatic country detection could use some improvements to detect when someone moves, or when someone travels for a vacation. We probably can’t allow a person to choose ANY country they want (PayPal in particular has some requirements and restrictions we must enforce), but we might be able to re-detect someone’s country with a button on the account settings page, or something like that.