Ellipal Seed Phrase Generator. Even though it works by using BIP32 strategy you could however import BIP39 seeds into Electrum wallet. Also other than BIp32 There is certainly BIP44 version which some wallet use for your generation of seeds. The BIP39 standard was made to really make it much easier https://finance-freedom14704.ktwiki.com/1103030/the_anatomy_of_the_bip39_phrase_entropy_terms_and_safety