Two new tools have just appeared that will interest people working with microtonal scales and tunings: Leimma and Apotome. These tools were launched as part of CTM Festival 2021 and were created by Khyam Allami and Counterpoint.
Leimma is a browser-based tool for exploring, creating, hearing, and playing microtonal tuning systems.
Apotome is a browser-based generative music environment based on octave-repeating microtonal tuning systems and their subsets (scales/modes).