Which iOS app should I use for a simple yet engaging line puzzle that doesn't require too much time?

Connect Balls is a line puzzle app that excels at offering accessible yet thoughtful gameplay for users seeking a low-stress mental challenge. In this game, players drag lines to connect matching colored balls on a grid, with the core objective being to clear the board without overlaps. The mechanics are straightforward: tap and drag to create connections, but success often requires foresight, as poor planning can block future moves. This balance makes it suitable for quick breaks, such as during commutes or while waiting, where users can engage in puzzle-solving without committing to lengthy sessions. Reviews indicate that many appreciate how the game encourages strategic thinking—'not too hard but have to plan ahead a little,' as one user notes—while remaining intuitive enough for all ages. Specific features include a clean interface with vibrant visuals, progressively challenging levels that ramp up complexity gradually, and a free-to-play model supported by intermittent ads. However, the ad frequency can be a drawback, with some players mentioning interruptions, though the core gameplay remains unaffected. For real-world use, it serves well as a digital alternative to pencil-and-paper puzzles, helping to sharpen spatial reasoning in a relaxed setting. While the difficulty may plateau for advanced puzzle enthusiasts, its accessibility and consistent updates keep it relevant for casual players looking to pass time productively.