Comparison

Ring Sizer vs OneOpen

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

Head to head
About

Ring Sizer

Features
Read full description

Ring Sizer : Finger Size helps you estimate ring and finger sizes using simple measurement tools and size reference guides. Check finger measurements, compare sizing standards, and find the right ring size with an intuitive interface. Browse size charts, convert between common ring sizing systems, and save measurements for future reference. The app is designed to make ring sizing quick, convenient, and easy to understand. Whether you're buying a ring, planning a gift, or checking your own size, Measure Ring & Finger Size provides a practical way to estimate ring measurements from your device. To find out more about automatic subscription renewals: - Ad-free version - measure your ring unlimited Premium Subscription: MeasureRing One Week - 4.99 USD MeasureRing One Year - 19.99 USD Your payment will be charged to your iTunes Account. The app is offering auto-renewable subscriptions. For More Information: Privacy Policy : http://mastertexfab.com/pages/Privacy%20Policy.html Terms of Use : http://mastertexfab.com/pages/Terms%20Of%20Use.html

About

OneOpen

Features
Read full description

OneOpen is a multi-format file viewer for iPhone and iPad. Open documents, web pages, CAD drawings, 3D models and archives from Files, Mail and apps that support document sharing. HTML and Markdown Preview HTML, HTM and XHTML pages. Read Markdown / MD notes with headings, a table of contents, tables, code fences, task lists, footnotes and reference links. ZIP websites retain local images, styles and relative resources. Markdown in packages can display supported local images. Ordinary HTML allows restricted HTTPS/WSS networking by default, with offline and Safe Preview options. Markdown does not run scripts or load remote images. CAD drawings and 3D models (Advanced) โ€ข Pan, zoom and toggle layers in supported DWG/DXF 2D model-space drawings. โ€ข Rotate STEP/STP, IGES/IGS, BREP/BRP, STL, OBJ and PLY models, including PLY vertex colors and point clouds. โ€ข ZIP a complete OBJ model folder to load supported MTL materials, PNG/JPEG textures, normals, transparency and groups. A standalone OBJ shows geometry without reading private neighboring files. โ€ข Preview supported static GLB / glTF 2.0 geometry, nodes, basic materials and PNG/JPEG textures. Model ZIPs retain relative resources. JSON and model information have separate views. โ€ข USDZ starts in object view; choose AR when needed. โ€ข Included models and engineering drawings demonstrate supported features. Everyday viewing is free Read PDF, Office/iWork, images, audio/video, JSON, XML, YAML, CSV, code and text. PDF supports continuous reading, zoom, search and page controls that hide while scrolling. Edit supported text in an independent working copy. Archives and EPUB Browse ZIP, 7Z, RAR, TAR, GZ, BZ2, XZ and supported TAR combinations. Open or share supported entries and save extracted files to Files. ZIP and EPUB remain free; other archive formats require Advanced Access. EPUB follows the declared chapter order, with a table of contents, previous/next controls, current-chapter search and reading settings. Pages stay offline. A chapter error keeps navigation available. DRM, media overlays, annotations and whole-book search are unsupported. Email, certificates and information Decode EML headers, body text, common character encodings and attachment filenames. Open or share readable attachments independently. HTML email becomes text without loading remote content. Decryption, signature verification and TNEF extraction are not provided. Inspect public CER, DER, CRT and PEM certificate subjects, issuers, validity, algorithms, public keys, usages and SHA-256 fingerprints. Certificates are never installed and device trust is not evaluated. File Information includes PDF metadata, image/camera properties, media tracks, text encoding/line counts and archive summaries. Open from other apps Skippable onboarding uses real iOS screenshots to explain More, Edit and favorite ordering in the share sheet. Revisit it in Settings. Categories, Recents and widgets help you return to files. Advanced Access and compatibility An annual membership or a one-time lifetime purchase unlocks the same specialized features. Check format details before purchasing. DWG supports selected 2D model-space content; DXF supports text files. CAD editing, engineering measurement, native SolidWorks and full external references are unsupported. Compressed glTF geometry, skins and active morphs require conversion. Animation is static; advanced materials may be approximate. ZIP complete model folders, or use self-contained GLB for single-file sharing. Supported AES/ZipCrypto ZIPs prompt for passwords; unsupported encryption/compression, multipart and RAR3 solid are excluded. Native previews depend on iOS codecs/variants. Privacy No account, ads, analytics or document uploads. Non-HTML previews stay offline. HTML and ZIP websites may run JavaScript and connect over HTTPS/WSS in an isolated environment; offline and Safe Preview modes are available. Terms: https://oneapps.studio/terms Privacy: https://oneapps.studio/privacy

Screenshots

Ring Sizer4 screens
OneOpen4 screens

Verdict

The call

The clearest difference is ads: OneOpen at none against Ring Sizer's shown. OneOpen also leads on update cadence (every 3 days vs fortnightly). On price, in-app purchases, 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. Ring Sizer sells 2 in-app purchases, starting at $4.99 per 7 days and OneOpen sells 2 in-app purchases, starting at $0.99 per year. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Ring Sizer ships an update fortnightly, OneOpen every 3 days. Both last shipped on October 24, 2026.

Scorecard2 real differences ยท 4 level
Ring Sizer versus OneOpen: the parameters behind the verdict, then further details
ParameterRing SizerOneOpen
PriceFreeFree
Update frequencyFortnightlyEvery 3 days โ€” better
AdsYesNo โ€” better
In-app purchasesYesYes
DevicesiPhoneiPhone, iPad โ€” better
Requires iOS16.6 โ€” better17.0
Further details โ€” not scored
Size62 MB73 MB
Age rating4+4+
DeveloperMastertex FabFreedom Dimension (shenzhen) Technology Co., Ltd

In-app purchases

2 purchases

Ring Sizer

Subscriptions2
  • MeasureRing One Week$4.997 Days
  • MeasureRing One Year$19.991 Year
2 purchases

OneOpen

Subscriptions1
  • Advanced Access Annual$0.991 Year
One-time1
  • Advanced Access Lifetime$2.99

Questions

Is Ring Sizer free?
Ring Sizer is free to download, with in-app purchases available.
Is OneOpen free?
OneOpen is free to download, with in-app purchases available.
Do Ring Sizer or OneOpen have ads?
Ring Sizer shows ads; OneOpen does not.
Which is updated more often, Ring Sizer or OneOpen?
Ring Sizer ships an update fortnightly, and OneOpen every 3 days. Most recently, Ring Sizer was updated on October 24, 2026 and OneOpen on October 24, 2026.

Other comparisons