Apple iOS is a close-code eco system. All applications need to live inside the sandbox so they cannot interace with other application. Because of this reason, developers have very limited ability to write a powerful app. Actually, there are many powerful apps for iOS in the market, you can get it from the 3rd party App store named "Cydia". With all these tweaks, your iPhone will even more powerful than you think it is.
Apple iOS core system is locked so many useful features are not available at the App Store. With Cydia, these features (or plugins) are able to install at your iOS and you can use it system wide. One of the example is to extend the control center, you can then remove useless toggles and add your recent use toggles to the list. Compose a SMS with just a single type on any applications without quick the app that are running. There are still many other plugins you will find it useful after jailbreak.