Comparison

Know Your Lemons vs Runfa.st

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

Head to head
About

Know Your Lemons

This app empowers users to take control of their breast health. It offers personalized risk assessment, monthly self-exam reminders, and educational tools to understand symptoms and prepare for screenings. Track your cycle and learn how to perform self-exams with confidence.

Highlights
  • Monthly self-exam reminders
  • Personalized risk calculation
  • Screening plan creation
  • Audio self-exam guides
  • Menstrual cycle tracking
  • Learn 12 breast cancer symptoms
Features
Read full description

Don’t wait to find a breast problem before you learn about breast health! Earn your two lemons and become a Lemonista Confidence: Play games and follow guided lessons to learn how to do a breast self-exam. Intelligence: Complete the Tyrer-Cuzick risk assessment to learn about your personal risk and get a custom screening plan. Make it part of your health routine with monthly self-exam reminders, badges, tools to help you prepare for screening, and helpful guides on what to do if you find something. Created by the Know Your Lemons Foundation, winner of the 2025 Webby Award for Best Health, Wellness & Fitness app. As a charity, security and privacy are important to us. Data collection is to prevent losing information and to enable additional features. Your health data is securely stored, is not sold to third parties, and your account and its data can be deleted at any time.

About

Runfa.st

Features
Read full description

Runfa.st is the personal AI running coach that actually understands your data. Stop relying on generic, static training plans that don't adapt to your fitness level. Runfa.st analyzes your real training history to build dynamic weekly plans and give you actionable, specific advice tailored to your exact goals. Whether you’re chasing your first 5K, aiming for a sub-1:30 half marathon, or hunting down a marathon PB, Runfa.st replaces the guesswork with data-driven guidance so you can improve with purpose. Key Features: • Dynamic Weekly Plans: Get a tailored day-by-day schedule featuring easy runs, intervals, tempo efforts, and long runs—each with the exact target paces you need to hit your goal. • Hyper-Personalized AI Coach: Chat with an AI that knows your actual running stats. Ask how to adjust your pace, what you're missing in your training, or why a run felt hard—and get highly specific, data-backed answers. • Seamless Apple Health Sync: Instantly import your Apple Fitness workouts (including Strava runs synced to Apple Health) so your coach and plans are always up to date. • Race Targeting: Set your event date, distance, and goal time. See exactly how many days are left and track your average paces to ensure you're on track for race day. • Target-Specific Threads: Training for multiple races? Keep your coaching chats organized by specific targets so the context never gets lost. • Minimalist, Distraction-Free Design: A beautifully bold, dark-mode interface built to keep you focused on what matters—your training, your progress, and your next run. Runfa.st requires an active subscription to access all features including AI coaching, personalised weekly training plans, race target tracking, run imports, and stats analysis. Subscription plans are available on a weekly or monthly basis. Payment is charged to your Apple ID account at confirmation of purchase. Subscription automatically renews unless cancelled at least 24 hours before the end of the current period. AI coaching includes a monthly usage allowance that resets automatically. No additional purchases are available or required. Terms of Use: https://www.tapable.app/runfast/terms Privacy Policy: https://www.tapable.app/runfast/privacy

Screenshots

Know Your Lemons4 screens
Runfa.st4 screens

Verdict

The call

The clearest difference is in-app purchases: Know Your Lemons at none against Runfa.st's 2. Know Your Lemons also leads on iOS requirement (15.0 vs 26.0). Runfa.st's advantage is update cadence (every 2 days vs fortnightly). On price, ads 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

Both are free to download. Runfa.st sells 2 in-app purchases, starting at $4.99 per 7 days. Know Your Lemons asks for nothing beyond the download.

UpkeepUpdate frequency

Know Your Lemons ships an update fortnightly, Runfa.st every 2 days. The most recent releases landed on October 14, 2026 and September 30, 2026 respectively.

Scorecard3 real differences · 7 level
Know Your Lemons versus Runfa.st: the parameters behind the verdict, then further details
ParameterKnow Your LemonsRunfa.st
PriceFreeFree
Rating4.8 (125 ratings) — better—
Positive reviews77.1% of reviews—
Number of ratings125 — better—
Update frequencyFortnightlyEvery 2 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhone, iPod — betteriPhone
Requires iOS15.0 — better26.0
Further details — not scored
Size196 MB20 MB
Age rating4+9+
DeveloperKnow Your Lemons Foundation Inc.Jan Zarcky

Bugs and requests

Know Your Lemons

Reported bugs

9 issues
  • Reminder notifications are consistently wrong (early or not sent)
  • Risk assessment quiz restarts mid-quiz
  • User data disappears after a period
  • Unable to log back into the app after initial use
  • Age selection in screening quiz is limited and buggy
Show 4 more
  • Main screen content overlaps on some devices
  • Incorrect website URL mentioned in video
  • Notifications not received
  • Login screen pop-up doesn't appear

Requested features

9 requests
  • Adjustable reminder timings for varying cycle lengths
  • Reminders to stay on Lock Screen/icon badge
  • More inclusive language for transgender individuals
  • Inclusion of UK/global location data
  • Update recurrence statistics with current data
Show 4 more
  • More detailed risk assessment considering subtype and stage
  • Fix for risk assessment quiz restarting
  • Fix for data disappearing
  • Fix for login issues and re-entry problems

Runfa.st

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Know Your Lemons

No in-app purchases

2 purchases

Runfa.st

Subscriptions2
  • Runfast Weekly Subscription$4.997 Days
  • Runfast Monthly Subscription$9.991 Month

Questions

Is Know Your Lemons free?
Know Your Lemons is free to download, with no in-app purchases.
Is Runfa.st free?
Runfa.st is free to download, with in-app purchases available.
Do Know Your Lemons or Runfa.st have ads?
Neither Know Your Lemons nor Runfa.st shows ads.
Which is updated more often, Know Your Lemons or Runfa.st?
Know Your Lemons ships an update fortnightly, and Runfa.st every 2 days. Most recently, Know Your Lemons was updated on October 14, 2026 and Runfa.st on September 30, 2026.

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