It can be frustrating to use software, devices or apps that are hard to use. From complicated user interfaces to unintuitive controls, there are many reasons why something can be difficult to use. Luckily, there are plenty of synonyms to describe these types of frustrating experiences. You might describe something as cumbersome, tricky, convoluted or perplexing. Other words to use might include bewildering, daunting, unintelligible, or obscure. Whatever words you choose, don't hesitate to speak up and provide feedback on things that are hard to use - it's the only way to improve the user experience!