Comparison

e vs Relativistic Space

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

Head to head
About

e

Explore the universe of spacetime by converting lengths into time and vice versa. This unique calculator uses geometrized units to help you think about the world in new ways and amuse your friends. It's a fun tool for science enthusiasts and students alike.

Highlights
  • Convert length to time
  • Convert time to length
  • Geometrized units (c=1)
  • Avoids scientific notation
  • Supports various input units
  • Educational and entertaining
Read full description

Have you thought about how old you are - in meters? Or how tall you are - in seconds? Or how many miles it is until your next birthday? Let's think out of the box, relativistically. While spacetime intervals are constant, length and time can be converted to each other. This calculator makes use of geometrized units (where the speed of light is unity) and lets you convert conveniently between length and time. Is this a useful conversion tool in your day-to-day life? Probably not. But maybe it will let you think about the world a little differently. And amuse your friends and family at the same time! For a technical reference, refer to "Gravitation", by Misner, Thorne and Wheeler, 1973, W.H. Freeman and Company, pp. 35-36. To make things more accessible to the average user, we have tried to avoid displaying scientific notation in numbers as much as possible and, instead, make use of more common terms, such as "billions of miles" and "milliseconds". Now upgraded with the ability to choose different lengths and times for input (inches, hours, days, etc.)! keywords: science, physics, space, time, relativity, calculator ---------------- Reviews from around the world: from Fox Knight, US Love this app!! from highschool student, US Good job, there's a lot of potential here. . . from Turbo elf, US Science geek must buy from Letter Warrior, US I love this idea, especially seeing how far it is until tomorrow, or a friend's birthday. from Professor and wife, US A great application that can also be used by students ... really is a wonderful game.

About

Relativistic Space

This educational tool simulates the behavior of space and time at high speeds. Developed as part of a master's dissertation, it focuses on relativistic effects without considering acceleration.

Highlights
  • Relativistic velocity simulation
  • Space-time behavior visualization
  • Pedagogical tool
  • Master's dissertation project
Features
Read full description

This simple simulator shows how space and time behave at relativistic velocities. It was developed as a pedagogical tool as part of a master's dissertation at the Federal University of Espírito Santo. Thus, it does not take into account the acceleration effects of the spacecraft. It was developed in a partnership between Prof Thiéberson Gomes (UFES), Prof Flávio Gimenes (UFES) and student Luiz Henrique Gobbi, with computational support Rodrigo Marques.

Screenshots

e4 screens
Relativistic Space4 screens

Verdict

The call

The clearest difference is rating: e at 5.0 against Relativistic Space's 3.7. e also leads on update cadence (every 11 months vs every 75 months). Relativistic Space's advantage is review sentiment (100% vs 90%) and ratings volume (3 vs 1). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

e holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews complicate that: 90% of e's written reviews are positive against 100% of Relativistic Space's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

e ships an update every 11 months, Relativistic Space every 75 months. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

Scorecard5 real differences · 5 level
e versus Relativistic Space: the parameters behind the verdict, then further details
ParametereRelativistic Space
PriceFreeFree
Rating5.0 (1 ratings) — better3.7 (3 ratings)
Positive reviews90.0% of reviews100.0% of reviews — better
Number of ratings13 — better
Update frequencyEvery 11 months — betterEvery 75 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.513.0 — better
Further details — not scored
Size4 MB52 MB
Age rating4+4+
DeveloperElliptics, Ltd.Thieberson Gomes

Customer experience

e

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews10 reviews
Positive90.0%
Neutral0.0%
Negative10.0%

Relativistic Space

All ratings2 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

e

No in-app purchases

None

Relativistic Space

No in-app purchases

Questions

Is e free?
e is free to download, with no in-app purchases.
Is Relativistic Space free?
Relativistic Space is free to download, with no in-app purchases.
Which has better reviews, e or Relativistic Space?
e is rated higher. e averages 5.0 out of 5 from 1 ratings, while Relativistic Space averages 3.7 from 3 ratings.
Do e or Relativistic Space have ads?
Neither e nor Relativistic Space shows ads.
Which is updated more often, e or Relativistic Space?
e ships an update every 11 months, and Relativistic Space every 75 months. Most recently, e was updated on November 6, 2026 and Relativistic Space on November 3, 2026.

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