Comparison

Periodic Timer + vs Wobble Rowing

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Periodic Timer +

This app provides a simple, repeating interval timer that works in the background. It offers customizable sounds, vibration, and flexible output modes for various activities like fitness, cooking, and learning. The interface is designed to be minimalist and distraction-free.

Highlights
  • Repeating interval timer
  • Customizable sounds and vibration
  • Works in the background
  • Long intervals up to 99 hours
  • Multiple timer output modes
  • Shake to start functionality
Features
Read full description

Keep track of time without being distracted by the device! Simple and easy timer that repeats at your chosen interval. FEATURES - Many sounds to select + the ability to add custom ones. - Up to 4 pinned and up to 5 recent Quick Start items. - Long intervals - up to 99 hours! - Vibration, if the sound is off. - Works in the background. - 3 timer output modes: intervals, total time, countdown. - You can cancel or pause the timer with help of a notification. - Flexibility and minimalism. - Shake To Start - can be enabled in settings. - Prevent Lockscreen - another useful setting, the screen will not lock, while the timer is running. USE CASES Here is a list of use cases based on the real feedback: Fitness and health: - Stretching - Stationary bicycle (interval training) - On a treadmill - For HIIT - Jogging - Timed medication - Boxing Cooking - While frying potatoes - Roasting steaks - Checking an oven or a grill to prevent burning Learning & science - Foreign language learning - As a lab timer - Periodic data collection - Speech training - Presentation timing Other - Mindfulness - Communication - To have a sense of time flying away :) HELP Q: Why the timer doesn't work in the background? A: You should allow notifications. Q: How to turn off the sound and turn on the vibration? A: On the device, turn the Silent Mode on. (Side Switch) Q: How can I add a custom sound? A: There are four ways. Choose one depending where is the sound file located. * If the sound on your Mac or PC: 1. Connect the device. 2. Open Finder and select the device. 3. Select Files in the menu. There you'll find 'Periodic +' folder. 4. Drug and drop the sound file there. * From Files app on iPhone: 1. Copy the required file. 2. Open Periodic + folder and paste it. * From another app on iPhone (like Mail): 1. Open the app where the file is located. 2. Find and touch Share button (it may have different name, for example Export). 3. In the appearing Share Sheet find the list of apps. If there is no Periodic +, touch More and enable it. 4. Now select Periodic + in the Share dialog and the sound will be imported. * And the most convenient "+" button! 1. Open Sounds tab. 2. Hit the "+" button in the "Folder" section and pick your file. Q: Alert is limited for 5 seconds! A: Go to Settings app, then Periodic + > Notifications > Banner Style > Persistent. Q: How to switch the Timer Output Mode? A: To switch the Output Mode touch the timer display at the top of the screen. Q: What is Shake To Start for? A: Shake To Start setting allows to start/cancel the timer by shaking the device. Thus, you don't touch the screen, what can be useful while cooking, for example. For this mode, in order to work, the app should be open. This app has a free version with limited features. If you still have questions or suggestions, you can visit the support page (https://goo.gl/forms/pggVBcaBxdW85EGE3), the Facebook group (http://www.facebook.com/groups/PeriodicTimer/) or you can email me (periodictimer.sup@gmail.com). If you like the app - please, rate it!

About

Wobble Rowing

This app measures the stability of your rowing shell in real-time, calculating a "Wobble Factor" to help you improve your technique. It also tracks stroke rate and pace, providing per-minute summaries and saving detailed data for analysis.

Highlights
  • Measures shell stability (Wobble Factor)
  • Tracks stroke rate (SPM)
  • Monitors pace (min/500m)
  • Real-time data capture
  • Per-minute session summaries
  • CSV data export for analysis
Features
Read full description

Wobble Rowing measures the stability of your rowing shell during training and racing. In the spirit of "You can't improve what you don't measure", Wobble Rowing captures the motion of your shell and calculates the Wobble Factor which is a measure of how much your boat is rocking side to side. What Wobble Rowing measures: Wobble Factor — shell stability in real time Stroke Rate — strokes per minute Pace — minutes per 500 meters After each session: A per-minute summary shows your average pace, stroke rate, and wobble factor so you can track improvement over time. A CSV file is saved to your iPhone for detailed analysis. The CSV file captures data 10 times a second. Privacy: No personally identifiable data is collected. An anonymous ID is used to contribute data to a research database to help improve the model. GPS is used only to determine speed and location. Wobble Rowing is always free.

Screenshots

Periodic Timer +4 screens
Wobble Rowing4 screens

Verdict

The call

The clearest difference is review sentiment: Wobble Rowing at 100% against Periodic Timer +'s 54%. Wobble Rowing also leads on price (Free vs $4.99) and rating (5.0 vs 3.9). Periodic Timer +'s advantage is ratings volume (74 vs 2) and chart position (#124 vs unranked). On update cadence, ads, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Wobble Rowing is free to download; Periodic Timer + costs $4.99 up front. Periodic Timer + sells 3 one-off in-app purchases. Wobble Rowing asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Wobble Rowing holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: Periodic Timer + has 74 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 54% of Periodic Timer +'s written reviews are positive against 100% of Wobble Rowing's.

UpkeepUpdate frequency

Periodic Timer + ships an update every 4 months, Wobble Rowing every 2 months. The most recent releases landed on October 19, 2026 and October 8, 2026 respectively.

Scorecard6 real differences · 5 level
Periodic Timer + versus Wobble Rowing: the parameters behind the verdict, then further details
ParameterPeriodic Timer +Wobble Rowing
Price$4.99Free — better
Rating3.9 (74 ratings)5.0 (2 ratings) — better
Positive reviews53.6% of reviews100.0% of reviews — better
Number of ratings74 — better2
Update frequencyEvery 4 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreeFree
Best chart rank#124 — better—
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size12 MB0 MB
Age rating4+4+
DeveloperVladimir KelinWilliam North

Customer experience

Periodic Timer +

All ratings74 ratings
Positive67.6%
Neutral9.5%
Negative23.0%
Written reviews84 reviews
Positive53.6%
Neutral14.3%
Negative32.1%

Wobble Rowing

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Periodic Timer +

Reported bugs

14 issues
  • Doesn't work in background
  • Timer doesn't work for over 59 minutes on watch
  • Custom alert audio not working
  • Alarm not working after payment
  • App doesn't open
Show 9 more
  • Timer restarts automatically
  • External speaker volume lower
  • Battery drain on Apple Watch
  • Timer stops going off after a certain number of reps
  • App crashes
  • Sound uses sound effect volume on iPad
  • Heart rate sensor stays on when running in background
  • Timer restarts automatically
  • Volume barely audible

Requested features

23 requests
  • More sound options
  • Ability to set alarm for a time of day
  • Explanation for changing display mode
  • Simultaneous timers
  • Ability to set start/end times and weekdays
Show 18 more
  • Customizable notification text
  • Apple Watch complication
  • Widget support
  • Longer vibration duration
  • Lap count and current lap time display
  • Ability to set custom alert audio
  • Option to set alarm for a specific time of day
  • Ability to set multiple timers simultaneously
  • Ability to specify number of loop cycles
  • Option to use custom MP3 files for alerts
  • Control vibration duration
  • Synchronize with iOS clock
  • More diverse vibration modes
  • Ability to add custom notification sounds
  • Turn off Apple Watch function
  • Fix iPad sound volume control
  • Add more timers
  • Make timer not restart automatically

Wobble Rowing

Not enough reviews yet to summarise bugs or requests.

In-app purchases

3 purchases

Periodic Timer +

One-time3
  • Tip a Banana$0.99
  • Tip a Coffee$3.99
  • Donate: Bust the project!$9.99
None

Wobble Rowing

No in-app purchases

Questions

Is Periodic Timer + free?
Periodic Timer + costs $4.99, and also offers in-app purchases.
Is Wobble Rowing free?
Wobble Rowing is free to download, with no in-app purchases.
Which has better reviews, Periodic Timer + or Wobble Rowing?
Wobble Rowing is rated higher. Periodic Timer + averages 3.9 out of 5 from 74 ratings, while Wobble Rowing averages 5.0 from 2 ratings.
Do Periodic Timer + or Wobble Rowing have ads?
Neither Periodic Timer + nor Wobble Rowing shows ads.
Which is updated more often, Periodic Timer + or Wobble Rowing?
Periodic Timer + ships an update every 4 months, and Wobble Rowing every 2 months. Most recently, Periodic Timer + was updated on October 19, 2026 and Wobble Rowing on October 8, 2026.

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