Safari Plus is a tweak for jailbroken iDevices that aims to bring features Apple should have included by default in the Safari browser for iOS. Enhanced downloads, upload any file and force HTTPS with Safari Plus.
Myriam Security Challenges is a tool to help you learn iOS exploitation. It's a tool aimed at beginners, so if you don't know anything about exploiting iOS, this is a good chance to start as the tool just scored an update.
The NFC chip has been locked down my Apple since its announcement with the iPhone 6. It's a pity, however, the famous developer Elias Limneos has managed to break the restriction on jailbroken devices.