While many tools require a computer, a few "semi-untethered" options can be installed via third-party app stores like IPA-Apps .
Open Safari and visit a reputable signing service like IPA-Apps. Search for Freya or Chimera and tap "Get" or "Install".
For users on older hardware, jailbreaking offers several practical benefits: What is Jailbreaking & Is it safe? - Kaspersky