Sounds like you could be a pro for building wallets! Actually, if you're interested in helping out with Cashu with exactly those two skills (JS and React) you could be the first person to implement a native mobile wallet! It's fairly easy to do, the only complicated part is the token cryptography but that's all already implemented in the LNbits web wallet and basically copy and paste.

Let me know what you think, you can hit me up on Telegram or Twitter under the handle "callebtc".