Bip39 generator with balance https://685fcc02d9ea2.site123.me Regardless that it uses BIP32 process you could even now import BIP39 seeds into Electrum wallet. Also besides BIp32 There exists BIP44 version which some wallet use with the generation of seeds. For words that only have 3 letters, there is absolutely no 4th letter. https://socialwebconsult.com/story5860278/bip39-golang-the-smart-trick-of-bip39-word-list-github-that-no-one-is-discussing-https-x-com-tundra838554