AppBandit is a security-focused proxy built on top of SecApps online security testing suite. With AppBandit you are not just getting a brand new, modern proxy but also additional workflows and tooling not seen anywhere else.
AppBandit is straightforward to get started with. If you have experience with other intercepting proxies, the setup process is more or less the same. Nevertheless, check the setup tutorials to ensure everything is set properly for your OS of choice.