I built RightLayout because every keyboard-layout corrector I tried for macOS broke on names, code, and typos. It was a small bet: train a CoreML model from scratch, three layouts, on-device. It worked. Then the maintenance bill came due, and I open-sourced it.
1. The problem with dictionary punto-switchers
If you type in two or three languages on a Mac, you have lived this. You start a sentence in English, the layout is still on Russian, and the screen fills with Cyrillic noise. The fix exists in theory. There are tools that watch your input and flip the layout when the word "looks wrong".
The classical version of that tool is dictionary-based. It checks each word against a frozen vocabulary and corrects when the word does not appear. That works for the easy cases. It also fails the moment a real human starts typing real text.
Names break it. Code breaks it. Acronyms break it. URLs break it. The word kubectl is not in any Russian dictionary, but it is also not a wrong-layout English word. A typo like helo is missing from the dictionary, so the tool helpfully turns it into руды. And in mixed-language paragraphs the dictionary does not even know which language to anchor against.
A dictionary check has no idea what you are typing. It can be solid and polished and still get the same class of false positives, because the underlying signal is the wrong one. You need something that reads context, not vocabulary.