The ConsenSys Diligence team has built a lot of tools with use cases ranging from automatic vulnerability discovery (check out MythX) to network-based vulnerability scanning (TeaTime), to code understanding tools (Surya, VSCode visual developer).
Check out all our tools here: Blockchain Security Tools | ConsenSys Diligence
A few months ago, we released Scribble, an all-new specification language for smart contracts. Using Scribble, you can extend your smart contract with specifications that we can automatically check using fuzzing and symbolic execution techniques.