Comparison

R2 Touch vs ConvertX

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

Head to head
About

R2 Touch

This app serves as a remote control for R2-D2 replica robots equipped with specific receiver boards. It allows users to control various droid functions like dome panels, holoprojectors, sounds, and lighting. Users can upload their own sound files for playback and customize button commands.

Highlights
  • Control dome panels, holoprojectors, sounds, and lighting
  • Upload custom sound files
  • Programmable ASCII string commands
  • WiFi and serial output options
  • Customizable buttons
  • R2-D2 inspired interface
Features
Read full description

This is a remote control app for members of the R2 Builders Club. Apart from looking pretty, and playing sounds (if you upload them to the application), it doesn't do anything unless you are building an R2-D2 replica robot and have MarcDuino receiver boards (as described in www.marcduino.com and on my build log on Astromech.net). If you do, lucky you, it will allow you to control the dome panels, holoprojectors, sounds and dome lighting of your Droid in all sorts of interesting ways. You can see a demo of how it works with my R2 here: http://www.youtube.com/watch?v=AUod3LRQ1DI The app can run all the way down to iOS 8 on an iPhone 4S. The app doesn't include any sounds by default. If you want sounds to play directly from the app or through Bluetooth, you must upload your own sounds files to the App using iTunes. The sound files are typically the exact same you'd use in your remote sound system of the robot such as my MP3Trigger setup (described on www.marcduino.com). Commands, in the form of programmable short ASCII strings, are sent via the internal WiFi iPhone radio to a remote WiFly receiver. Alternately, the app also generates a 9600 baud serial output stream on the earphone audio port. This way you can send serial command to an external XBee transmitter radio for a more reliable link. You'll need a small level adapter board to use the audio serial capability, also on www.curiousmarc.com. Since you can customize most buttons and commands, you could also use this as a generic remote control app to send any short serial string via WiFi (to a WiFly radio fore example) or serial link (through an XBee). And with a spiffy R2-D2 inspired interface to boot!

About

ConvertX

Features
Read full description

Convert any unit in seconds with ConvertX — a powerful unit converter for engineers, students, professionals, and everyday use. From everyday measurements to advanced engineering conversions. -> 400+ UNITS ACROSS 44 CATEGORIES Quickly convert everyday and technical measurements, including: • Length — meters, kilometers, miles, feet, inches • Weight & Mass — kilograms, grams, pounds, ounces • Temperature — Celsius, Fahrenheit, Kelvin • Area — square meters, square feet, acres • Volume — liters, milliliters, gallons • Speed — km/h, mph, m/s • Time — seconds, minutes, hours, days • Data Storage — bits, bytes, KB, MB, GB • Pressure — Pa, bar, psi, atm • Energy — joules, calories, kWh • Power — watts, kilowatts, horsepower • Angle — degrees, radians • Frequency — Hz, kHz, MHz • Fuel Efficiency • And many more measurement conversions -> CURRENCY CONVERTER Convert between 30+ currencies using live exchange rates. Currency data can be cached for convenient access when an internet connection is unavailable. -> ENGINEERING CONVERSIONS — PRO Convert advanced engineering and scientific measurements with dedicated tools for professional and technical use. Mechanical Engineering: • Force • Torque • Stress • Density • Dynamic & Kinematic Viscosity • Acceleration • Angular Velocity Civil Engineering: • Flow Rate • Stress Intensity • Illuminance • Concentration • Water Hardness Electrical Engineering: • Voltage • Resistance • Capacitance • Inductance • Current Density Thermal & HVAC: • Thermal Conductivity • Heat Flux • Cooling Load • Specific Heat Science: • Radiation Dose • Radioactivity • Molar Amount Material Science: • Hardness — HRC, HV, HB, Shore • Elastic Modulus -> FAST AND EASY TO USE Convert measurements quickly with a clean interface designed for everyday and professional use. • Large, easy-to-read results • Swap units with one tap • Copy results to your clipboard • Save frequently used conversions to Favorites • View your recent conversion history • Fast calculations • Clean dark interface • Unit calculations work offline -> OFFLINE UNIT CONVERTER Convert units without an internet connection. Everyday and engineering calculations work directly on your device, making ConvertX useful at home, at work, in classrooms, laboratories, workshops, engineering sites, and while traveling. -> BUILT FOR ENGINEERS, STUDENTS & EVERYDAY USERS ConvertX is useful for: • Mechanical Engineers • Civil Engineers • Electrical Engineers • HVAC Technicians • Engineering Students • Science Students • Technicians • Construction Professionals • Material Scientists • Chemistry & Physics Students • Teachers • Developers • Travelers • DIY Users -> SIMPLE & PRIVATE No account is required to use ConvertX. Unit calculations work directly on your device, including offline conversions. Convert meters to feet, kilometers to miles, kilograms to pounds, Celsius to Fahrenheit, liters to gallons, psi to bar, watts to horsepower, and hundreds of other units in seconds. Whether you need a quick measurement conversion for everyday use or advanced engineering conversions for professional work, ConvertX brings everyday, scientific, engineering, and currency conversions together in one app. -> CONVERTX PRO Unlock all 29 engineering categories with a one-time purchase. Lifetime access. No subscription. One payment includes all current engineering categories and future engineering categories. Get ConvertX today and keep a powerful unit conversion toolkit at your fingertips. Whether you're an engineer, student, professional, traveler, or simply need a quick conversion, ConvertX makes everyday and technical unit conversions fast, simple, and convenient — even when you're offline.

Screenshots

R2 Touch4 screens
ConvertX4 screens

Verdict

The call

The clearest difference is price: ConvertX at Free against R2 Touch's $5.99. R2 Touch's advantage is in-app purchases (none vs 1) and ads (none vs shown). On update cadence 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

ConvertX is free to download; R2 Touch costs $5.99 up front. ConvertX sells 1 one-off in-app purchase. R2 Touch asks for nothing beyond the download.

UpkeepUpdate frequency

R2 Touch ships an update every 10 months, ConvertX every 7 months. The most recent releases landed on November 1, 2026 and November 9, 2026 respectively.

Scorecard4 real differences · 6 level
R2 Touch versus ConvertX: the parameters behind the verdict, then further details
ParameterR2 TouchConvertX
Price$5.99Free — better
Rating4.8 (9 ratings) — better—
Positive reviews80.0% of reviews—
Number of ratings9 — better—
Update frequencyEvery 10 monthsEvery 7 months — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPodiPhone, iPod
Requires iOS8.0 — better15.6
Further details — not scored
Size4 MB35 MB
Age rating4+17+
DeveloperNeil HutchisonDhaval Panasara

In-app purchases

None

R2 Touch

No in-app purchases

1 purchases

ConvertX

One-time1
  • LifeTime Premium$4.99

Questions

Is R2 Touch free?
R2 Touch costs $5.99, with no in-app purchases.
Is ConvertX free?
ConvertX is free to download, with in-app purchases available.
Do R2 Touch or ConvertX have ads?
ConvertX shows ads; R2 Touch does not.
Which is updated more often, R2 Touch or ConvertX?
R2 Touch ships an update every 10 months, and ConvertX every 7 months. Most recently, R2 Touch was updated on November 1, 2026 and ConvertX on November 9, 2026.

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