World Flags Flashcards
Here is a collection of national flags from most countries in the world. The images are mostly from Clker and Wikimedia Commons. As for what areas count as distinct countries, there may be some dispute. Also, national flags change over time. Regardless, here are 224 national flags. The flags are all in the public domain.
If you're looking for Anki flashcards, here you go. These cards have the flag image on the front and the country name in English on the back. A nice thing about
SVG images is that they scale to any size and still look pretty. After you import this deck, play around with the card formatting and see what works best for you. The current settings look good on my smart phone, but if you're using a computer you might prefer something larger.