Opal is praised for effectively helping users manage screen time and improve focus. Users appreciate its ability to create friction that discourages compulsive app use, leading to a healthier relationship with their devices. Some find it particularly useful for maintaining focus during work and relaxing on weekends by blocking distracting apps. While some users mention the cost as a downside, the overall sentiment is positive, with many noting significant behavioral changes. The app's integration with iOS 16's Screen Time API is highlighted as a key feature.