The typing practice below wants a real keyboard layout, not a substitute; the drill reads whatever your operating system sends it. Both systems already carry every layout on this page, so nothing needs downloading or buying, and adding one takes about a minute.
On a Mac
On Windows
For the layout shown
The letters printed on your keys will not change. Both vendors point at the on-screen viewer as the way to find out which key produces which character; the alternatives are keycap stickers, or learning the positions, which is what the drill below is for.
Korean and Chinese are not layouts in the ordinary sense; what you add is an input method, and the software assembles the characters as you type. Windows files them under Add a keyboard regardless.
A practice keyboard for the Indigenous NT Integrated Keyboard — Dene, Cree, Gwich'in and eight more languages of the Northwest Territories. It works differently to the layouts on this page (Alt Gr, not an operating-system layout, so nothing above about adding it in System Settings applies). The characters are verified against the keyboard's own source file; drill sentences for the eleven languages, checked with a speaker the way the sentences below are, are not built yet.
لوحة المفاتيح العربية
Arabic Mac 102. Shift carries the harakat, the tanween and the lam-alef ligatures.