Bip39 wallet app https://ameblo.jp/generate-bip39brooks/entry-12913353546.html Despite the fact that it works by using BIP32 technique you could nevertheless import BIP39 seeds into Electrum wallet. Also apart from BIp32 There's BIP44 Model which some wallet use to the technology of seeds. For words that only have 3 letters, there's no 4th letter. https://bookmarkingquest.com/story20534388/bip39-to-seed-the-single-best-strategy-to-use-for-bip39-word-list-txt-https-t-me-bip39-chat