Cydia is one of the best Tweaked app stores for iOS. To use Cydia, you’ll need to jailbreak your iPhone. And if you consider doing it, it’s a fantastic App Store replacement. All the apps on this app store are jailbroken which does not restrain the usage of the app. But, if you are someone who values the security of their device more than anything, then move on to the next app store.
Also, read the best hacking app for Android.
The UI is fabulous and easy to navigate. You’ll notice similarities between the default app store since it looks like an exact copy. You can also change the theme of Cydia. Download it from the link below.