Comparison

Sputnik! vs Graph Calc Plus

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

Head to head
About

Sputnik!

Track the International Space Station and bright satellites with precise timing and location data. Get second-by-second countdowns, set reminders, and view satellite paths in the night sky. Supports offline calculations and sharing sightings.

Highlights
  • Accurate satellite and ISS sighting predictions
  • Starlink satellite train detection
  • Second-by-second countdowns
  • Sighting reminders
  • Compass direction and elevation display
  • Night sky path visualization
  • Offline calculations
Features
Read full description

Sputnik! is an easy to use tool for predicting when the International Space Station will pass by your location or when a bright satellite will be visible in the skies above. Sputnik! features: - Predictions of satellite and ISS sightings accurate to the second. - Detection of Starlink satellite trains. - Second by second countdown to the satellite sighting. - Set reminders of upcoming satellite sightings. - Displays compass direction and elevation for your device to easily find the part of the sky where the sighting will occur (requires capable device). - Rotate your device to landscape orientation to show exactly where the satellite will pass in the night sky. - Share sightings via Twitter, Facebook, Mail, Messages and others. - Automatic download of up to date satellite orbital data. - Offline calculations, no need to be connected to the internet once orbital data has been downloaded. - Input your location automatically by GPS, select from a map or enter coordinates manually. - Save your favorite places for easy access. - Audio cues for the last seconds before the satellite passes by. Sputnik! on Apple Watch: - Easily find the next and last sighting at your current location. * Sputnik! is ad-supported *

About

Graph Calc Plus

Features
Read full description

Graph Calculator define the graph of [f] to be the graph of the equation y = f(x). So, the graph of a function if a special case of the graph of an equation. Features: ∙ Set individual line color. ∙ Show/Hide individual mathematical expression. ∙ Pinch to Zoom in/out Graph View. ∙ Pan to reposition Graph View. ∙ Add up to 22 mathematical expressions. ∙ Full screen preview. Graph Features: ∙ Custom background color for Graph. ∙ Custom grid color for Graph. ∙ Show/Hide Grid Lines/Minor Grid Lines. ∙ Show/Hide Axis Number. ∙ Show/Hide X-Axis. ∙ Show/Hide Y-Axis. ∙ Set Graph Line Width range from 0.5~5.0. Some of the most commonly used functions: y = mx + b y = x**2 [x²] y = x**3 [x³] y = sqrt(x) [√x] y = ln(x) y = log(x) y = sin(x) y = cos(x) y = tan(x) Standard Operators: + - addition and unary positive - - subtraction and negation * - multiplication / - division ! - factorial ** - pow, exponentiation sqrt(x) - square root cuberoot(x) - cubic root Standard parameters (constant): phi - returns the value of ϕ (the Golden Ratio). Also recognized as ϕ() pi - returns the value of π. Also recognized as π() pi_2 - returns the value of π/2 pi_4 - returns the value of π/4 tau - returns the value of τ. Also recognized as τ() sqrt2 - returns the value of the square root of 2 e - returns the value of e log2e - returns the value of the log base 2 of e log10e - returns the value of the log base 10 of e ln2 - returns the value of the log base e of 2 ln10 - returns the value of the log base e of 10 Standard Functions that take 1 parameter: sqrt() - returns the square root of the passed parameter log() - returns the base 10 log of the passed parameter ln() - returns the base e log of the passed parameter log2() - returns the base 2 log of the passed parameter ceil() - returns the passed parameter rounded up floor() - returns the passed parameter rounded down Trigonometric functions: sin(), cos(), tan() Their inverses (asin, acos, atan, atan2) Their reciprocals (csc, sec, cotan) The reciprocals of the inverses (acsc, asec, acotan) The hyperbolic variations of all the above functions (sinh, cosh, tanh, asinh, acosh, atanh, csch, sech, cotanh, acsch, asech, acotanh) The versine functions (versin, vercosin, coversin, covercosin, haversin, havercosin, hacoversin, hacovercosin, exsec, excsc, crd) dtor() - converts the passed parameter from degrees to radians rtod() - converts the passed parameter from radians to degrees Quick Start: 1. Tap on [+] button. 2. Change the equation of the line to y=3x+1 and see graphed. 3. You can also enter equations that are not solved for x e.g. x=2y+2 About Graph Calculator In mathematics, the graph of a function f is the set of ordered pairs (x,y), where f(x)=y. In the common case where x and f(x) are real numbers, these pairs are Cartesian coordinates of points in two-dimensional space and thus form a subset of this plane. Thanks for your support and do visit nitrio.com for more apps for your iOS devices.

Screenshots

Sputnik!4 screens
Graph Calc Plus4 screens

Verdict

The call

The clearest difference is price: Sputnik! at Free against Graph Calc Plus's $2.99. Sputnik! also leads on update cadence (every 5 months vs every 39 months). Graph Calc Plus's advantage is in-app purchases (none vs 1). On ads, 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

Sputnik! is free to download; Graph Calc Plus costs $2.99 up front. Sputnik! sells 1 one-off in-app purchase. Graph Calc Plus asks for nothing beyond the download.

UpkeepUpdate frequency

Sputnik! ships an update every 5 months, Graph Calc Plus every 39 months. The most recent releases landed on September 23, 2026 and December 13, 2025 respectively.

Scorecard3 real differences · 7 level
Sputnik! versus Graph Calc Plus: the parameters behind the verdict, then further details
ParameterSputnik!Graph Calc Plus
PriceFree — better$2.99
Rating4.7 (731 ratings) — better—
Positive reviews92.2% of reviews—
Number of ratings731 — better—
Update frequencyEvery 5 months — betterEvery 39 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationAd-supported—
DevicesiPhone, iPod, Apple WatchiPhone, iPad, iPod
Requires iOS14.014.0
Further details — not scored
Size35 MB1 MB
Age rating4+4+
DeveloperApplicate LtdHeng Jia Liang

Bugs and requests

Sputnik!

Reported bugs

3 issues
  • App reporting 'No Sightings' for all categories
  • Null check errors when selecting satellite sightings
  • Issues with location settings and data updates

Requested features

4 requests
  • Add support for more satellite types
  • Improve sky chart visualization and orientation
  • Provide filtering options (e.g. by elevation, magnitude)
  • Implement automatic data updates

Graph Calc Plus

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Sputnik!

One-time1
  • Go ad-free$0.99
None

Graph Calc Plus

No in-app purchases

Questions

Is Sputnik! free?
Sputnik! is free to download, with in-app purchases available.
Is Graph Calc Plus free?
Graph Calc Plus costs $2.99, with no in-app purchases.
Do Sputnik! or Graph Calc Plus have ads?
Neither Sputnik! nor Graph Calc Plus shows ads.
Which is updated more often, Sputnik! or Graph Calc Plus?
Sputnik! ships an update every 5 months, and Graph Calc Plus every 39 months. Most recently, Sputnik! was updated on September 23, 2026 and Graph Calc Plus on December 13, 2025.

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