Why does my phone Pomodoro timer stop when I lock the screen?

This is caused by OS battery optimization shutting down background processes. On Android: Settings > Battery > Battery Optimization > find your app > set to Not optimized. On iOS: enable Background App Refresh for the app in Settings.

Can I use a browser timer on my phone instead of an app?

You can, but browser timers on mobile are less reliable when the phone locks or you switch apps. For reliable alerts, a dedicated app is better for mobile use.

Are mobile Pomodoro apps worth paying for?

The free tiers of most mobile Pomodoro apps cover core functionality adequately. Paid upgrades add task management, statistics, and themes. For most users, the free tier is sufficient.

Best Mobile Pomodoro Timer Apps — Focus Sessions Anywhere

When You'd Use a Mobile Pomodoro Timer

A mobile Pomodoro timer is most useful when you're working away from your primary computer — studying in a library, working at a coffee shop, handling tasks on a tablet, or managing your secondary work device. It's also useful when your phone serves as your primary computing device, which is increasingly common for certain types of remote and freelance work.

The key advantage of a phone timer over a browser timer: background processing. iOS and Android both allow apps to continue running timers when backgrounded, which means your Pomodoro session keeps counting down even when you're actively using the phone for research, messaging, or taking notes. A browser timer in a mobile browser tab often doesn't have this reliability.

What Makes a Good Mobile Pomodoro App

Mobile timer apps have specific requirements that differ from desktop and browser versions.

Reliable background operation: The timer must keep running and deliver an alert when you switch to other apps or lock the screen. This is the most critical feature and the most variable across apps.
Haptic feedback: On mobile, a vibration alert is often more useful than sound alone — it works when the phone is on silent or in a pocket during a session at a quiet location.
Offline operation: Mobile apps should work without internet access. A timer that requires a data connection to function has unacceptable failure modes.
One-tap start: Opening an app and tapping start in under 3 seconds. Apps that require session setup before timing create friction that mobile users especially resist.
Lock screen widget or notification: Being able to see the remaining time on the lock screen without unlocking the phone reduces the temptation to engage with the phone during sessions.

Options for iPhone Users

iOS Pomodoro app options worth knowing:

Forest (free / paid): Plants a virtual tree during sessions that dies if you leave the app. The gamification is effective for some users; irrelevant for others. Background timer works reliably. Social features in paid tier.
Be Focused Pro ($4.99): Clean iOS design, reliable background operation, configurable intervals, task list integration. One of the most polished iOS options.
Focus Flow (free / paid): Minimal UI, ambient sound options, reliable alerts. Good choice for users who want background audio with their timer.
Timer+ (free): Not specifically Pomodoro but fully configurable countdown timer with reliable iOS background operation. Add your own intervals.

Test background behavior before committing. Start a session, lock your phone, wait 3 minutes, then check if the timer is still accurate. Some apps pause when the screen locks, which makes them unreliable for Pomodoro use.

Options for Android Users

Android Pomodoro options:

Focus To-Do (free / paid): Combines Pomodoro timing with task management. Reliable Android background operation. Clean notification with remaining time. Free tier is functional.
Pomodoro Timer Lite (free): No-frills Android timer. Configurable intervals, reliable background operation, no account required. Functional and fast.
Forest (free / paid): Same as iOS version. Background operation reliable on Android; some older versions have issues with aggressive battery optimization — check app settings.
Brain Focus (free): Open-source approach, clean design, configurable intervals, optional website blocking via the Android accessibility service. Reliable and free.

Android users should check battery optimization settings for whichever app they choose — Android's aggressive background app management can prevent timers from firing reliably. Whitelisting the Pomodoro app from battery optimization ensures alerts arrive on time.

Tips for Staying Focused with a Phone Timer

The irony of using your phone as a Pomodoro timer is that the phone itself is the primary distraction you're trying to avoid. A few strategies that resolve this conflict:

Enable Do Not Disturb with timer exception: Most mobile OS's allow you to enable DND while whitelisting specific apps (like your timer app) to send notifications. This silences distracting notifications while preserving session-end alerts.
Place the phone face-down: Keep the phone on the desk but face-down. This physically removes the visual temptation of the notification LED and prevents screen-on notifications from pulling attention.
Use Focus Mode (iOS) or Digital Wellbeing (Android): App blocking during sessions, controlled by the timer app start/stop, is the most effective phone distraction solution — using the phone itself to manage phone distraction.
Pair with a secondary timer: Some mobile Pomodoro workers keep a browser timer open on their laptop as primary, with the phone in DND and face-down, eliminating phone-as-distraction entirely while still having alerts available via laptop.