If you remember the good old days when you could visit a web page in mobile Safari and swipe your finger over a virtual slider to achieve a jailbreak (yes, I’m pointing at you JailbreakMe), then we’ve got some good news for you.
iOS hacker and developer Sem Voigtländer (@UKERN Software) appears to be working on a JailbreakMe-styled tool that you can visit in mobile Safari that theoretically supports iOS firmware versions from 4.0 to 12.0.1 (*with some exceptions*).