I am the developer of the Android app “Keyboard Designer” (keyboarddesigner.com), which is a fully customizable keyboard, but it does not offer any word corrections, yet. Currently I am working on a word bar to implement this missing feature and I am testing some word correction algorithems.
As the Keyboard Designer does not request any permissions, it does also not request to connect to the internet. Is it possible to use the Language Tool without the need to access internet? If possible I would like to import the required word list by the app by text or I offer additional APK files in the Play Store for each language.
Have a nice day