At the latest since Ableton Push came out its key layout became popular. This key layout is called isomorphic note layout. But this idea is not new; accordions using various isomorphic keyboards have been built since the 19th century.
In contrast to Push’s in key mode all notes are part of the layout, so you can play notes, which are not in scale. From my point of view this allows musicians more creativity. Use Push’s chromatic mode, if you like go this way.
If you don’t own a Push, you can try one of the iPad apps like Musix.
The main advantage of this layout is the transpositional invariance. That means chords have the same shape when transposed to another key. So, you can transpose the following shapes by moving them horizontal or vertical.
Robbie James from Lostbeat made wide-ranging tables of shapes for chromatic and
in key mode. Have fun with it! alexander