Here is the list
iOS, using App Store, used Objective-C to program with Swift being compile-compatible meant to surpplant the old OC. With further restriction is Mac OS and Xcode, which you have, likely $200 for a business tier publishing account (required).
Android, the golden standard, using Google Play, Java to program with Kotlin being compile-compatible modern substitute for Java, minus the above-mentioned restriction; all 3 major computing platforms and either Official IDE or SDK toolchain can be used, likely $150 for business tier but the other roll-out options are another store company or unrestricted side-load (iOS needs Jail Break to do this)
Windows Phone, using Windows Store (same as desktops) is nearly identical to what Android offers and cost except the language is C#, must use Windows to program and there's no other store company.
Apache Cordova is JavaScript and have simulated visual binding to create iOS, Android, or Windows Phone apps and publish to the respective store. If a language is compile-compatible to its predecessor it means those two languages can share same API, same project, and compiles to the same binary or byte code.
All platforms require XML as a layout language, be that in the form of Android, Windows XAML, Cordova HTML, or whatever. BlackBerry and Tizen are not viable contenders and I do not wish to describe them.