Calistra Viewer vs CNC For U
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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.
CNC For U
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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
Verdict
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
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.
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.
| Parameter | Calistra Viewer | CNC For U |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (4 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 4 — better | — |
| Update frequency | Every 6 days — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad | iPhone, iPod |
| Requires iOS | 26.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 345 MB | 48 MB |
| Age rating | 4+ | 12+ |
| Developer | CHANCELLOR G KREMER | Udhayakumar Natarajan |
In-app purchases
Calistra Viewer
- Pro Upgrade$6.99
CNC For U
- CNC2 variants$1.991 Month





