Author

Manuel Rozewski

SimOptions Team
358 Guides written38 Guides reviewed

Part of the SimOptions team, tech and travel savvy, and it takes more than two hands to count the countries he has visited. Before a guide goes live, Manuel takes it for a spin on real iPhones and Androids, tapping through every step so you don't get stuck at arrivals. When he isn't testing, he writes about eSIM basics and picking the right plan.

Guides written

358
Updated October 20, 2026Phones & eSIM CompatibilityHow to Unlock Your Phone From Your Carrier: Step-by-Step GuideTo unlock your phone, you ask the carrier that sold it. Only that carrier can remove the lock. Once the phone is paid off and has been active long enough, AT&T, Verizon…13 min readMarch 12, 2019eSIM BasicsWhat is an eSIM?No matter where we go, we always need to stay connected with our family, friends or our boss. No matter if we just move from one city to another or we are just visiting…4 min readMarch 5, 2019SIM Cards ExplainedHow are SIM Cards, Carriers & Mobile Numbers Related?Technology changes every single day and it has been improving without stopping during the last years. Sometimes we wonder many technological things about our cell…5 min readMarch 3, 2019Updated October 21, 2026SIM Cards ExplainedCDMA vs GSM: What Is the Difference, and Does It Still Matter?CDMA vs GSM: what is the difference? Both are older (2G and 3G) ways for a mobile network to share its radio signal between many phones. GSM gives each call its own…11 min readFebruary 24, 2019eSIM BasicsInternational SIM Card vs Local SIM Card vs Data RoamingThe number one benefit of information technology is that it empowers people to do what they want to do. It lets people be creative. It lets people be productive. It…8 min readOctober 3, 2018Mobile Data & RoamingWhat is The Best Portable WiFi Router?Just like you, I realized that my internet needs are ever-growing. As I become more and more connected, I think that everyone deserves better than the airports’ free…5 min readOctober 2, 2018Travel TipsBest Cities For Sightseeing In EuropeThis continent is definitely one of the best to visit on vacation. No matter if you are going during winter or summer. No matter if you are traveling alone or with your…9 min readSeptember 21, 2018Travel TipsThe 6 Best Places to Visit In USAIf you have never been in the United States and you have the curiosity about how life is supposed to be there, you need to read this article. It will offer excellent…10 min readSeptember 19, 2018SIM Cards ExplainedThe Ultimate Guide to SIM CardsSIM Cards seem so simple - You plug it into your smartphone and most of the time, it works right away. Once you start digging deeper, you realize that these SIM Cards…17 min readSeptember 19, 2018Travel TipsThe Strangest City Names Around The WorldEvery city name has an interesting history behind. Some of them are due to the person who discovered that place. Some others have its name because of an emblematic…8 min readSeptember 12, 2018Travel Tips30 Tips & Tricks How To Travel With KidsTraveling with kids it does not necessarily mean an impossible mission. This could be the best family experience on vacation if you prepare yourselves. Here you will…10 min readSeptember 1, 2018Travel TipsWhat Are The Worst Tourist Traps In The World?Many places around the world offer tourists wonderful things that at the end of the story are just lies. Sometimes they are - just a little bit – true, but they are not…10 min readAugust 28, 2018