Timefinder is the best time boxing app I've found (and I've tried most of them). The app is easy to use, imports calendar events well, provides solid customization options, and might be (from the apps I've tested) the only fully cross-platform Apple app (available on macOS, scales well on iPad and iPhone) I've seen for time boxing. The app syncs pretty seamlessly across devices, too. The developer is also super responsive and open to feedback, which I've thoroughly appreciated. Luke has helped me troubleshoot any problem I've had within the same day. Timefinder fits right into my workflow even though I use multiple tools (calendar apps/Things/Notion) to organize my time - it's right up there with the tools that I use most. The ability to see all events within certain time boxes and time box additional events/tasks without having those sync directly to my calendar has been great and provides me with an efficient way to plan out any free time I have without impacting my calendars directly. Love TimeFinder!
Thanks so much for sharing your experience with my timeboxing app! I’m so glad to hear that it works so well for you as a schedule planner alongside your calendar and other productivity tools. Stay tuned for even more third-party app integrations (like Todoist and Things 3) coming later this year—made possible thanks to your feedback and support. Thank you! -Luke