Comparison

Calistra Viewer vs CNC For U

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

Head to head
About

Calistra Viewer

This application allows engineers, machinists, and designers to view and inspect complex 3D CAD models on iOS devices. It supports a wide range of file formats and offers tools for measurement, material assignment, and weight calculation, all while operating fully offline.

Highlights
  • Supports STEP, IGES, STL, OBJ, glTF, GLB, PLY, VRML, BREP formats
  • Precise measurement of dimensions, angles, and lengths
  • Material assignment and weight calculation
  • Wireframe, shaded, and edge display modes
  • Fully offline operation, no account or internet needed
  • Apple Pencil support with hover previews
Features
Read full description

Calistra Viewer opens your 3D models and 2D drawings instantly and lets you inspect, measure and share them — with the speed and precision of a professional CAD kernel, on your iPhone and iPad. 3D MODELS • Open STL, OBJ, glTF/GLB, PLY, 3MF, VRML, USDZ/USD and JT files • Buttery 120 fps orbit, pan and zoom — even on very large meshes • Exact measurements: distances, diameters, radii, angles, edge lengths, areas • Instant unit switching between millimeters and inches • Weight & Material: pick from a curated library of metals, plastics and composites and see the model's mass instantly • Part browser for multi-body files — isolate, hide and show components • Beautiful photoreal shading out of the box 2D DRAWINGS • Open DXF and DWG drawings with exact geometry, layers and dimensions • Full drawing editor: draw, dimension, snap, measure and export • Measurements read in the drawing's true units BUILT FOR SPEED • Models open in a fraction of a second, from the very first launch • Hardware-accelerated rendering tuned for Apple silicon and 120 Hz displays • Full keyboard support on iPad: orbit, pan and zoom with the arrow keys, customizable shortcuts WORKS YOUR WAY • Open files from Files, iCloud Drive, AirDrop, Mail or any app's share sheet Whether you're checking a print before it hits the build plate, reviewing a supplier's part on the shop floor, or reading a drawing on site, Calistra Viewer gives you an exact answer, fast.

About

CNC For U

Features
Read full description

CNC FOR U is a powerful CNC program calculator designed for machining professionals and hobbyists. Instead of teaching programming concepts, this app allows users to input machining parameters and automatically generates accurate CNC G-code programs . Save time and reduce errors by quickly producing ready-to-use CNC programs based on your specific requirements. Key Features: Input your machining parameters with ease. Automatically generate CNC G-code programs . Share generated CNC programs directly from the app. Supports common G and M codes for precise machine control. No user data is collected or stored, ensuring privacy and security. Ideal for CNC operators and machinists who want a reliable tool to speed up program generation without manual coding. Simplify your CNC programming workflow with CNC FOR U.

Screenshots

Calistra Viewer4 screens
CNC For U4 screens

Verdict

The call

The clearest difference is update cadence: Calistra Viewer at every 6 days against CNC For U's monthly. CNC For U's advantage is iOS requirement (15.1 vs 26.0). On price, ads, in-app purchases 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. Calistra Viewer sells 1 one-off in-app purchase and CNC For U sells 1 in-app purchase, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Calistra Viewer ships an update every 6 days, CNC For U monthly. The most recent releases landed on August 30, 2026 and September 9, 2026 respectively.

Scorecard2 real differences · 8 level
Calistra Viewer versus CNC For U: the parameters behind the verdict, then further details
ParameterCalistra ViewerCNC For U
PriceFreeFree
Rating5.0 (4 ratings) — better
Positive reviews100.0% of reviews
Number of ratings4 — better
Update frequencyEvery 6 days — betterMonthly
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases
DevicesiPhone, iPadiPhone, iPod
Requires iOS26.015.1 — better
Further details — not scored
Size345 MB48 MB
Age rating4+12+
DeveloperCHANCELLOR G KREMERUdhayakumar Natarajan

In-app purchases

1 purchases

Calistra Viewer

One-time1
  • Pro Upgrade$6.99
1 purchases

CNC For U

Subscriptions1
  • CNC2 variants$1.991 Month

Questions

Is Calistra Viewer free?
Calistra Viewer is free to download, with in-app purchases available.
Is CNC For U free?
CNC For U is free to download, with in-app purchases available.
Do Calistra Viewer or CNC For U have ads?
Neither Calistra Viewer nor CNC For U shows ads.
Which is updated more often, Calistra Viewer or CNC For U?
Calistra Viewer ships an update every 6 days, and CNC For U monthly. Most recently, Calistra Viewer was updated on August 30, 2026 and CNC For U on September 9, 2026.

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