Shared bikes and e-scooters have spread to most large cities worldwide, but the brands are local more often than global, so do not expect the app from home to work. Lime and Bird operate in many countries, Citi Bike is New York specific, and a great many cities run their own municipal bike-share or have regional scooter operators instead. Some cities have banned rental e-scooters after trial periods, while their bike-share still thrives, so the two travel different paths.
Tourist areas are usually well covered where the schemes exist at all, since operators concentrate vehicles exactly where footfall is. Sign-up is generally quick with a foreign card, though some municipal bike systems require a local transit card or have clunkier registration for visitors.
The two-minute check before your trip: search which micromobility apps operate in that specific city, download and register in advance, and skim the local rules, since helmet requirements, sidewalk bans, minimum ages, and mandatory parking zones vary and fines land on your linked card. Then look at the app map on arrival; vehicle density on the map tells you instantly how useful it will really be.