TrailWallet app for Apple iDevices is superb. I've been through Guatemala to Ecuador and it handled currencies flawlessly. I like how it maintains daily budget amount spent and amount left in the budget. What I love is the way it helps with spending habits through in-app coaching! It works.
Now back in USA I continue to track expenses with the app. It's that useful.
Hobo Members save 1000's of dollars by joining HoboTraveler and asking pro travelers questions on the Hobo Talk Wall.