Cell phone coverage should of course be a major consideration when traveling overseas. I have faithfully used T-Mobile over the years and their plan continues to offer free international roaming to over 210 countries. Keep in mind though that your speeds are throttled to 2G in most cases. That being said, the slow 2G speeds are fast enough to do what I need when I am not on wifi, such as ordering an Uber, look up things to do or nearby restaurants, and check my email. Outside of the US I have found that almost everywhere has wifi, from not only coffee shops but also bars, restaurants, museums, and in some parks and plazas! In addition, if you travel to Mexico or Canada, you’re in luck. With a qualifying plan, you get unlimited talk and text here and up to 5G of LTE data. T-Mobile also offers $5 per 24 hour travel passes. The on-demand pass gives you 512MB of Internet and unlimited calling in 210+ countries in a 24-hour period. $5 a day is quite reasonable but it can add up rapidly. The 2G speeds are often fast enough to even make use of Apple FaceTime audio or Viber calls without being on wifi as well. Amazingly, I have yet found a need to upgrade to an international pass, even once.