Comparison

相対性理論計 vs Pocket Experiments Science Lab

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

Head to head
About

相対性理論計

Features
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Instead of a pedometer — Einstein’s “time drift.” A grand thought experiment (Gedankenexperiment) you can carry in your pocket. The formulas are real. The measuring is rough GPS. Walk. Take the train. Climb the stairs. Just living as usual already opens a tiny gap between you and “the you who stayed where you woke this morning.” Relativity Meter is an everyday toy for peeking at that stretch and squeeze of time hidden in a day’s steps — blown up to the absurd scale of × 10⁻¹⁴ seconds. • Blue = time slows (speed: special relativity) • Red = time advances (height: gravitational redshift) • The number on the home screen = today’s net drift from both We use Einstein’s equations as they are: Δt ≈ t·v²/(2c²) from special relativity (speed), and Δt ≈ t·gh/c² from general relativity — gravitational redshift (height). The sensor side is phone GPS. Not a lab instrument — a toy for finding wonder in ordinary steps. Privacy you can trust No account. Fully offline. Location is computed on-device only and is never sent to any server. (On Apple Watch, you can glance at today’s number on your wrist.) Optional dial-face pack The digital dial stays free. SF and cosmic dials include a 7-day on-device trial, then unlock with one non-consumable purchase (not a subscription). Made by Lagado Lab.

About

Pocket Experiments Science Lab

Features
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Twenty-six rooms. Not a workbook — a bench in each one. You set the parts out yourself, turn the knobs, and measure with the instruments. • Hang as many weights as you like anywhere along a balance beam, and even it up • Drag molecules onto the bench and see what they form • Set a magma's silica and the depth where it freezes, erupt it, then look at the rock through a hand lens and measure the grains • Stretch two strings, detune one, and listen to the beats • Drop three seismometers on a map; three circles meet at one point, and that point is the epicenter Every number is measured off the picture. Nothing here works a value out of a formula and then "checks" it against the same formula. The grains under the lens are really drawn, and their size is really measured. Turn a knob and the picture changes; when the picture changes, the numbers change with it. Every room has three steps: 1. Move it — turn one knob and watch what changes 2. Count it — line the measurement up against the formula and look at the gap 3. Check it — one question, and the reason either way Every room also has a question box. Clear it and the room moves up a tier: none → bronze → silver → gold. There are 78 questions in all. But the questions are not the main act. Playing with the bench is; a question is the detour you take when you think “wait — could I actually build that?” The topics are middle school and high school science: forces and motion, springs and buoyancy, pendulums, circuits, electromagnets, ray optics, lenses, sound, changes of state, solubility, titration, electrolysis, chemical reactions, preparing and collecting gases, the microscope, cell division, photosynthesis, flower structure, heredity, strata, rocks and volcanoes, earthquakes, and the sky. Three neighbors of science come along too: probability, logic gates and regular expressions. ADS AND THE ONE-TIME PURCHASE The app is free and shows ads: a banner along the bottom of the screen, and a full-screen ad when you open the app. All 26 rooms and all 78 questions are open from the first launch. There is exactly one in-app purchase and all it does is turn the ads off — it unlocks nothing and adds nothing. It is a single one-time purchase with no subscription (¥5,000 in Japan; the price for your country is shown in the app). Not based on, or affiliated with, any particular textbook.

Screenshots

相対性理論計4 screens
Pocket Experiments Science Lab4 screens

Verdict

The call

The clearest difference is in-app purchases: 相対性理論計 at none against Pocket Experiments Science Lab's 1. 相対性理論計 also leads on ads (none vs shown) and update cadence (daily vs every 9 days). On price, device support and iOS requirement 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. Pocket Experiments Science Lab sells 1 one-off in-app purchase. 相対性理論計 asks for nothing beyond the download.

UpkeepUpdate frequency

相対性理論計 ships an update daily, Pocket Experiments Science Lab every 9 days. The most recent releases landed on October 13, 2026 and October 24, 2026 respectively.

Scorecard3 real differences · 3 level
相対性理論計 versus Pocket Experiments Science Lab: the parameters behind the verdict, then further details
Parameter相対性理論計Pocket Experiments Science Lab
PriceFreeFree
Update frequencyDaily — betterEvery 9 days
AdsNo — betterYes
In-app purchasesNo — betterYes
DevicesiPhone, Apple WatchiPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size8 MB12 MB
Age rating4+4+
DeveloperTAKEHITO AWASHIMAMIZOU, CO., LTD.

In-app purchases

None

相対性理論計

No in-app purchases

1 purchases

Pocket Experiments Science Lab

One-time1
  • Remove Ads$29.99

Questions

Is 相対性理論計 free?
相対性理論計 is free to download, with no in-app purchases.
Is Pocket Experiments Science Lab free?
Pocket Experiments Science Lab is free to download, with in-app purchases available.
Do 相対性理論計 or Pocket Experiments Science Lab have ads?
Pocket Experiments Science Lab shows ads; 相対性理論計 does not.
Which is updated more often, 相対性理論計 or Pocket Experiments Science Lab?
相対性理論計 ships an update daily, and Pocket Experiments Science Lab every 9 days. Most recently, 相対性理論計 was updated on October 13, 2026 and Pocket Experiments Science Lab on October 24, 2026.

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