Comparison

Notesync.md vs Dioptra

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

Head to head
About

Notesync.md

Features
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Notesync.md is a simple notes app built for organizing quick project thoughts into folders, notes, and timeline-style entries, then keeping them synchronized across Mac, iPhone, and iPad with iCloud. Notes are also mirrored to the local filesystem as Markdown files, making them easy to read, back up, edit, or use with project management agents and other developer workflows.

About

Dioptra

Features
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A 3D model viewer for iPhone and iPad that takes measurement seriously. Open a file, turn it over, and tap two points on the surface to get a real distance. FORMATS โ€ข glTF โ€” .glb and .gltf โ€ข USD โ€” .usdz, .usdc, .usda and .usd โ€ข STL โ€” 3D prints and CAD exports, read in millimetres and turned upright โ€ข PLY โ€” scans and photogrammetry, with per-vertex colour โ€ข VRM โ€ข Interactive pages โ€” an .html export keeps its own controls and runs as it was built MEASURE โ€ข Tap two points for a true distance โ€ข Take as many measurements as you need; they stay listed with the model โ€ข Switch between metric and imperial whenever you like โ€ข Set what one file unit means: metres, centimetres, millimetres, inches or feet INSPECT โ€ข Orbit, pan and zoom, or leave it turning on its own โ€ข Wireframe, to see how a mesh is built โ€ข Studio, light and dark backgrounds โ€ข Play embedded animations, one clip at a time โ€ข Model info: width, height and depth, plus triangles, vertices, meshes, materials, textures, nodes and animations โ€ข Share a snapshot of the view ORGANISE โ€ข Folders, which appear in the Files app exactly as they do here โ€ข Search, sort by name, type or date, and switch between a list and a grid โ€ข Rename, drag a model onto a folder to file it, or delete it โ€ข Bring models in with the picker, from another app's share sheet, or by dropping them into the Dioptra folder in Files SAMPLES Six models come with the app, one for each kind of file it opens, all built to real-world scale: the ancient sighting instrument the app is named for, a Roman surveyor's groma, a sundial's gnomon, a tripod foot in millimetres, a surveyed patch of terrain, and an interactive plan of sight lines. PRIVATE BY DEFAULT No account, no sign-in, no cloud, no tracking and no ads. Your models stay on your device and everything works offline.

Screenshots

Notesync.md3 screens
Dioptra4 screens

Verdict

The call

The clearest difference is in-app purchases: Notesync.md at none against Dioptra's 3. Notesync.md also leads on update cadence (daily vs fortnightly). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Dioptra sells 3 one-off in-app purchases. Notesync.md asks for nothing beyond the download.

UpkeepUpdate frequency

Notesync.md ships an update daily, Dioptra fortnightly. The most recent releases landed on November 5, 2026 and November 10, 2026 respectively.

Scorecard2 real differences ยท 4 level
Notesync.md versus Dioptra: the parameters behind the verdict, then further details
ParameterNotesync.mdDioptra
PriceFreeFree
Update frequencyDaily โ€” betterFortnightly
AdsNoNo
In-app purchasesNo โ€” betterYes
DevicesiPhone, iPad, Mac โ€” betteriPhone, iPad
Requires iOS17.017.0
Further details โ€” not scored
Size2 MB5 MB
Age rating4+4+
DeveloperKristopher LinquistZachary Griffin

In-app purchases

None

Notesync.md

No in-app purchases

3 purchases

Dioptra

One-time3
  • Small Tip$0.99
  • Tip$1.99
  • Generous Tip$4.99

Questions

Is Notesync.md free?
Notesync.md is free to download, with no in-app purchases.
Is Dioptra free?
Dioptra is free to download, with in-app purchases available.
Do Notesync.md or Dioptra have ads?
Neither Notesync.md nor Dioptra shows ads.
Which is updated more often, Notesync.md or Dioptra?
Notesync.md ships an update daily, and Dioptra fortnightly. Most recently, Notesync.md was updated on November 5, 2026 and Dioptra on November 10, 2026.

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