Opyn v2 allows you to create put and call options with spreads for capital efficiency, and is great for applications ranging from protection and hedging to taking views on different cryptocurrencies. Options are an incredibly versatile financial instrument - in fact you can create any financial payoff using just put and call options.
You can check out the projects that have integrated Opyn here! A number of them have open-source codebase that you can use to learn from as well.
Gamma Portal: an open-sourced alternative front end to interact with Gamma protocol
Ribbon: uses financial engineering to create structured products that deliver sustainable yield
Opeth: a synthetic instrument fusing options with the underlying asset to power liquidation free and capital efficient loans
Fontis: enables users to earn a yield by depositing assets into perpetual vaults trading options strategies
Optional: decentralized social trading for options
DEXTF: creates structured tokens making use of oTokens in the set of protocols they integrate from