If you are looking to build cross platform apps in FireMonkey for languages that read right to left (also known as bi-directional or BiDi support) there are a number of different solutions. One of those solutions is the FMXRTL library which I assume stands for FireMonkey Right To Left (verses RunTime Library). FMXRTL has a version for Delphi 10.2 Tokyo and Delphi 10.1 Berlin. Apparently part of how it works is there is a TFMXRTL component which changes some core objects in FireMonkey that handle text presentation. These changes cause BiDi support to trickle down to all of your existing FireMonkey controls. It doesn’t mention which platforms are explicitly supported by FMXRTL but I would assume Android, IOS, OSX, and Windows are probably supported. At the moment it appears that the FMXRTL package is free but also appears to be in beta or at least experimental. You may have to just download it and check it out for yourself to see if it can solve your BiDi needs. Some other BiDi solutions include using the Delphi HTML Component Library as your presentation layer or using TurboCocoa for your presentation layer (which allows you to use Xcode and Android Studio to build your interface).
FMXExpress.com has over 700 tips and tricks for building cross platform apps on Android, IOS, OSX, Windows, and Linux with a single codebase and single UI using the FireMonkey framework found in Delphi and C++Builder.
FMXExpress covers top cross platform secrets for FireMonkey in C++Builder and Delphi XE5, XE6, XE7, XE8, Seattle, Berlin, Tokyo, Rio, and Sydney.