If you are an Apple user then you must be knowing the there are some restrictions on your iPhone imposed by Apple, Such as you cannot install apps from third party sources (You only have to install apps from Apple Store).Also you cannot customize your iPhone much.
It was impossible until Cydia was developed. But you have to jailbreak your iPhone to use Cydia. Best alternative for Cydia is Bydia App for iOS.
You can use Cydia to install third party apps on your iPhone but the condition for using cydia is your iPhone device should be jailbroken, which is not advised so if you want to use cydia without jailbreak then we have compiled a list of Cydia alternatives including Bydia for iOS using which you can easily enjoy your favorite apps which are not available in apple store without taking the risk of jailbreaking your device.
Also See: iOS 10 Tips And Tricks
Cydia Alternatives without Jailbreak:
You can use these alternatives to install third party apps on your device without jailbreak.