Any time a checksum is invalid, alert the user which the phrase is not really a little something produced by your app, and ask if they would want to use it in any case. Using this method, your app only has to hold the wordlists in your supported languages, but https://allkindsofsocial.com/story4189708/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool