- Kali Linux - This is arguably the only tool you need in this category, as it has a curated, pre-configured collection of the absolute best tools in every category. Eventually, I'll put a descriptive list of all of those tools in here, but this is a tremendously powerful good start.
- Powershell Empire - A scarily-powerful Linux Powershell (yes, you read that right) and Python (sadly 2.6/2.7) compendium of post-exploit tools. I.E. you already have a credential, what can you do with it now?
- LastPass
- Firefox Lockbox
- 1Password
- Passbolt - Built for teams. Open source. Looks pretty solid.
- PicoCTF - A huge CTF game hosted by Carnegie-Mellon University.