So this happened when i was developing the iOS app for the company I work in. I was given half boiled code written by the previous employee to work on. The app was laid around a webview. Now in iOS, there are 2 kind of webviews, the UIWebView that works on all iOS versions, and the WKWebview that works only on iOS 8+.
The app was coded using UIWebview, I brouht that up with my boss, and he asked me to continue using it, even after I repeatedly informed him that the javascript engine of this webview is subpar and we could be better off with WKWebview. Fast forward to 12 weeks later. The application is ready and is given to the boss for testing. He runs the app and plays around for a day. The next day, he comes up to me and says "The javascripts aren't working that well, can we switch to WKWebview instead?" In the inside of my mind, I have already murdered him three times, on his face, however I say, "We can look into it."
So, basically I rewrote the whole app with WKWebView, retargetting the app to iOS 8+.
The app is tested and launched. Everythings fine. AND NOW, he comes up to me and says, "Can we switch it back to UIWebView? We really need the app to be universally available on the app store and 6% of our customers, still use iOS7."
You know how I felt and what I had to do. Goes without saying, that the application is available on the AppStore, targetting iOS 7+.

TLDR, iOS Dev, given half boiled code with UIWebview, tells boss about WKWebview (iOS8+) and advantages. He asks me to continue UIWebView. App developed, 12 weeks. He comes up and points to problems and asks me to retarget with WKWebview. Developed and App launched.
He comes up and says, we need iOS7+, retarget the app to UIWebview. FML.