If you are an experienced designer, you probably agree that being inspired by others is not stealing in UI design. It’s best practice research. It’s using design patterns. It’s following the guidelines. It’s making sure to use patterns that your users are familiar with to create usable interfaces.
Some might say that sticking to the guidelines and following others will kill creativity and, at the end of the day, all apps will look the same. From a UX perspective I see a different problem. Getting used to adapting best practices might make you believe that Google / Facebook / Instagram / [your favorite app here] is always right, their design goals are the same as yours and you fail to question them. Here are a few patterns that are (or used to be) considered best practices and yet might not be as good as you’d think at first sight.