I think I should know this but I'm new to using Google Wallet and have not used it for foreign travel. I've read that Google Wallet (formerly Google Pay) can be used to tap and pay on pubic transport in Istanbul and that unless we plan to use public transport a lot, it may be better to use Google Wallet for tap and pay instead of purchasing an Istanbulkart and having to figure out how much to load on it. We have a credit card with no foreign transaction fees in Google Wallet but will there still be some kind of fee each time we use it, or will it only charge the amont for travel on the tram, ferry, etc?