The US company usually launch iOS updates every so often, which also reach all compatible devices in the blink of an eye, something they can not say other systems such as Android or Windows Phone. However, this can become a problem for those users who jailbreak their devices.
Usually when Apple launches a new version fixes the bug that caused the jailbreak possible and users upgrading system must wait again. Although most of them prefer to wait and not upgrade to the latest version to keep the jailbreak.
To avoid the latter, Apple has made in the latest versions of iOS updates are automated, so that if pressed where you should begin to upgrade the device automatically at night without you noticing. However, there is a tweak that can be of great help to prevent iOS 9.3.4 is installed on your iPhone or iPad.
Discover Mikoto, the tweak will prevent iOS 9.3.4 is installed automatically
Previously, the software used to make the jailbreak was able to block automatically detect a new system update, so there was no worry about. But it seems that Pangu guys do not have that feature in its software and more than one user has lost the jailbreak.
If you have your device with the jailbreak done and want to avoid you upset like this there is a tweak that can not miss. It is Mikoto, a tweak that allows you to block update checking system which is available in the repo https://cydia.angelxwind.net/.
You have to add this repo to Cydia to download the tweak Mikoto. Once you've installed it , restart your device and go to tweak settings in the Settings menu, where you have to activate the "Software Update disabler" option.
This way you get updates via OTA (Over The Air) are not displayed on the device. So you no longer run the risk of losing the jailbreak inadvertently, as the latest version of iOS will not install unless you do it manually.