The variety of hardware devices and the diversity of their users imposes new requirements and expectations on designers and developers of mobile applications (apps). While the Internet has enabled new forms of communication platform, online stores provide the ability to review apps. These informal online app reviews have become a viral form of electronic word-of-mouth (eWOM), covering a plethora of issues. In our study, we set ourselves the goal of investigating whether online reviews reveal usability and user experience (UUX) issues, being important quality-in-use characteristics. To address this problem, we used sentiment analysis techniques, with the aim of extracting relevant keywords from eWOM WhatsApp data. Based on the extracted keywords, we next identified the original users' reviews, and individually assigned each attribute and dimension to them. Eventually, the reported issues were thematically synthesized into 7 attributes and 8 dimensions. If one asks whether online reviews reveal genuine UUX issues, in this case, the answer is definitely affirmative.