Bip39 online generator https://bip39marco.mystrikingly.com/ Mycelium - A mobile wallet that supports BIP39 seed phrases and it has advanced characteristics for electrical power consumers. For words that only have three letters, there is not any 4th letter. As an example With all the word “include”, there aren't any extra letters afterwards https://socialmediainuk.com/story23009082/bip39-ian-coleman-5-tips-about-bip39-checksum-you-can-use-today-https-dzen-ru-bip39-phrase-com