Comparison

STRNTH vs Mariabs · Interval Timer

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

Head to head
About

STRNTH

Features
Read full description

16 progressive programmes with planned deloads. Track every lift with 1RM, PRs and plateau alerts. Run HIIT with live heart rate. Get a weekly AI coach. Import your training history from another app. Strength training built for lifters in their 30s, 40s and beyond. Most apps are written for 25-year-olds. STRNTH is for people who have lifted before, or are starting now, and want to train for the long game. Open the app, your session is ready, and log a set in two taps. Free forever No card required, no time limit. These features stay free. - Workout logging across sets, reps and weight, including bodyweight, assisted and added load - Built-in programs with multi-week blocks and deloads baked in - Two-tap exercise swaps mid-workout - Rest and tempo timers with voice cues - HIIT preset library with Bluetooth heart rate and smart-trainer support - Body composition with caliper body fat, waist to height and fuel guidance - The STRNTH Index, PRs by muscle group and a year-long trend line - Customisable home dashboard with drag-and-drop widgets - Fatigue-aware readiness chip based on training stress and age - Ask STRNTH library of curated answers on training, recovery and nutrition - Workout history with charts, PR badges and exercise breakdowns - Progress photos with a before and after compare, locked behind Face ID - Import your workout history from other workout apps - Cardio logging for runs, rides, walks and swims, with pace and distance - Quick workouts and targeted sessions by muscle group or time - Adaptive resistance that holds your heart-rate zone on a smart trainer - Training block reviews with a shareable summary after each block - PT summary to hand your numbers to a personal trainer STRNTH Plus (Requires paid plan) Add custom content and unlock the full catalogue. - Custom programs: design a 4, 8 or 12 week block with your own splits and lifts - Custom workouts built from scratch - Custom HIIT with your own blocks and timing - Add your own exercises with muscle group tagging - Full program catalogue and full training history - Log workouts retroactively on past dates STRNTH Pro (Requires paid plan) Everything in Plus, with cloud backup and the age-aware AI coach. - Cloud backup. Sync across devices, reinstall without losing data - Age-aware AI coaching weekly review of readiness, training density and recent volume - Ask STRNTH AI: free-form questions answered with your last six months of training - Save adapted workouts when you change exercises mid-session - Plateau coaching when a lift stalls - Build this week from your recent training - Community programs: publish and enroll with other Pro members - Connect your AI assistant (beta, Pro) and build strength workouts, programmes and HIIT sessions - Build workouts and HIIT with AI by describing them in plain words Paid plan details STRNTH Plus and STRNTH Pro are auto-renewing paid plans, billed monthly or yearly. Payment will be charged to your Apple ID account at the confirmation of purchase. Your paid plan automatically renews unless canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage and cancel your paid plan in your account settings on the App Store. STRNTH is built by Billy, a developer-lifter who got tired of fitness apps that treated him like a 22-year-old. Quiet by design. Honest about pricing. Built for the long game. Terms of use: https://strnthapp.com/terms Privacy policy: https://strnthapp.com/privacy

About

Mariabs · Interval Timer

Features
Read full description

Mari is a sharp, minimal interval timer for anyone who trains in rounds — tabata, HIIT, EMOM, circuits, or your own custom intervals. Set your prepare, work, rest, cycles, blocks, and block-rest durations in seconds. Press the white play button. Mari counts you in, calls out each phase, and chimes the final 3-2-1 of every interval so you can keep your eyes on what you're doing instead of on the screen. WHAT YOU GET • Six adjustable parameters: prepare, work, rest, cycles per block, number of blocks, and rest between blocks • Voice cues for every transition: "Prepare", "Work", "Rest", and "Block complete — get ready for the next" • Distinct musical chimes per phase, generated on-device, synced with light haptics • 3-2-1 countdown ticks before each phase change • Big, monochrome timer dial with a subtle progress ring tinted to the current phase • Cycle and block progress shown at all times so you always know where you are • Plays over your music — Spotify, Apple Music, podcasts — and ducks them only when Mari speaks • Stays awake automatically while a workout is running • Settings remembered between launches DESIGNED TO STAY OUT OF THE WAY The screen is dark, glanceable from across a gym, and built around one button. There are no menus, no levels, no streaks, no badges, no analytics. You configure once, then press play. PRIVACY Mari collects nothing. No account. No email. No analytics. No tracking. Your settings stay on your device. The privacy policy is one page; you can read it before you tap install. NO ADS Mari has no ads, no in-app purchases, and no premium tier. No account required.

Screenshots

STRNTH4 screens
Mariabs · Interval Timer4 screens

Verdict

The call

The clearest difference is in-app purchases: Mariabs · Interval Timer at none against STRNTH's 5. On price, update cadence, 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. STRNTH sells 5 in-app purchases, starting at $4.99 per month. Mariabs · Interval Timer asks for nothing beyond the download.

UpkeepUpdate frequency

STRNTH ships an update every 5 days, Mariabs · Interval Timer every 6 days. The most recent releases landed on September 18, 2026 and September 21, 2026 respectively.

Scorecard1 real difference · 5 level
STRNTH versus Mariabs · Interval Timer: the parameters behind the verdict, then further details
ParameterSTRNTHMariabs · Interval Timer
PriceFreeFree
Update frequencyEvery 5 days — betterEvery 6 days
AdsNoNo
In-app purchasesYesNo — better
DevicesiPhone, iPad, iPod, Apple Watch — betteriPhone, iPad, Apple Watch
Requires iOS15.1 — better16.2
Further details — not scored
Size74 MB4 MB
Age rating4+4+
DeveloperNext Big Leap LtdPER MAGNE HELSETH

In-app purchases

5 purchases

STRNTH

Subscriptions5
  • STRNTH Plus Monthly$4.991 Month
  • STRNTH Pro Monthly$14.991 Month
  • STRNTH Plus Annual$44.991 Year
Show 2 more
  • STRNTH Pro Founder Yearly$54.991 Year
  • STRNTH Pro Yearly$99.991 Year
None

Mariabs · Interval Timer

No in-app purchases

Questions

Is STRNTH free?
STRNTH is free to download, with in-app purchases available.
Is Mariabs · Interval Timer free?
Mariabs · Interval Timer is free to download, with no in-app purchases.
Do STRNTH or Mariabs · Interval Timer have ads?
Neither STRNTH nor Mariabs · Interval Timer shows ads.
Which is updated more often, STRNTH or Mariabs · Interval Timer?
STRNTH ships an update every 5 days, and Mariabs · Interval Timer every 6 days. Most recently, STRNTH was updated on September 18, 2026 and Mariabs · Interval Timer on September 21, 2026.

Other comparisons