here is simple method to find jail breaking devices in swift.

Hopefully you checked on starting so put on starting view controller and call this function, if swift-

func DetectJailBreak() {   
let url = URL(string: "cydia://package/com.example.package")
if let url = url {
if UIApplication.shared.canOpenURL(url) {
let alert = UIAlertController(title: "Jailbroke Device found!!!", message: "This app can't be run in a Jailbroken device", preferredStyle: .alert)
DispatchQueue.main.async(execute: { [self] in
present(alert, animated: true)

Objective -C

NSURL *url = [NSURL URLWithString:@"cydia://package/com.example.package"];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Jailbroke Device found!!!" message:@"This app can't be run in a Jailbroken device"preferredStyle:UIAlertControllerStyleAlert];
dispatch_async(dispatch_get_main_queue(), ^{
[self presentViewController:alert animated:YES completion:nil];

Thank you!