Apple added a really useful feature to Siri, that lets you activate it hands-free just by saying “Hey Siri.” The feature sadly works only when your device is plugged in.
A new jailbreak tweak by well-known developer Hamza Sood called UntetheredHeySiri removes this restriction of being plugged in, and lets you use “Hey Siri” hands free activation all the time. So you’ll be able to activate Siri without pressing the home button, even when you aren’t plugged in.
The tweak is available on the Big Boss repo. After installing it from Cydia, you’ll have to enable the “Always” mode by going to Settings > General > Siri.
Note that Apple put the power-only constraint in place due to battery life concerns, so if you install this tweak, it’s likely you drain your battery faster than usual. We’re guessing iPhone 6 Plus owners can install this, given the larger battery, but even then, proceed with caution.