Developer jkour has released a tab control for Firemonkey in Delphi 10 Seattle. This new tab control allows you to build interfaces with Firemonkey similar to the tabs found in web browsers like Chrome and Firemonkey. The tab control is different than the built in TTabControl because it uses Frames for each tab. In addition to the Frames it allows you to name and access the tabs via a tag string. The tab control holds several tab items each tab item is a Frame. The tab button list can be customized with styles and it also supports mouse over preview of each tab which is a nifty feature. It has the option to set a right click menu on each tab button as well. The control is free on Github and available under the MIT license. There is a demo project which shows how to use it. I assume it should work under Android, IOS, OSX, and Windows. Obviously the mouse over and right click functionalities will only work on platforms that support a cursor. You may be able to use this control with C++Builder as well.
Head over and download the full source code for the unique frame based Tab Control for Firemonkey in Delphi 10 Seattle.