We use Travel Wallet - https://itunes.apple.com/app/id547171665?mt=8 - but I believe it’s only available for iPhone.
The app allows you to enter a home currency, then add up to 5 currencies per trip. Set your budget in the home currency, then add the foreign currency…with a tap of the summary screen, the budget will change to any currencies you added to the trip. Each destination is a trip for us.
The customizable categories (accommodations, restaurants, groceries) are great, so at the end of the trip we just download a CSV to do pivots, etc. There are columns in the CSV for local currency and foreign.
Hope this helps! Happy Travels.