To install these, you will need a computer (or a sideloading service like AltStore or SideStore). There is no magic "free web-based jailbreak" for modern iDevices. Understand that fundamental truth, and you will avoid 100% of Cydiaboxcom-style scams.
I should look for user experiences if possible. Are there others who have used it? Reviews on forums or social media might exist. But since it's not widely known, there might be limited info. I can only extrapolate based on similar sites. cydiaboxcom free
Even if a site manages to install a profile on your phone, you are giving a third-party developer high-level access to your device. To install these, you will need a computer
: Integration with tools like Winterboard or Dreamboard to completely re-skin the iOS interface with new icons and backgrounds. I should look for user experiences if possible
Apple actively fights against unauthorized third-party app stores.