It’s should probably be clarified that Kamesame does not require an actual Japanese keyboard. If you are using Windows, then installing Microsoft IME allows you to write Japanese anywhere in a similar fashion to how it works in the Wanikani input field (see here for a simple guide). There’s are equivalents on Linux and most likely also on OSX (I haven’t tried that myself). It’s also very easy to set up on mobile.
But while there is a bit of a learning curve for inputting stuff in Japanese, I’d strongly recommend KameSame over KaniWani. On top of getting you used to writing text in Japanese, it also allows you to study a large amount of kanji and vocab not found in WK.