Comparison

Design Materials vs OptiListen

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

Head to head
About

Design Materials

This app serves as an offline reference guide for various design materials, including polymers and metals. It allows users to manage their own material data, view 3D models, and capture objects with their device's camera. Ideal for professionals and hobbyists involved in product design and 3D printing.

Highlights
  • Offline material reference guide
  • Custom material and resin management
  • 3D model viewer and import/export
  • Object capture via device camera
  • Favorites and notes section
  • Cross-device compatibility (iOS, macOS)
Features
Read full description

Design Materials is an offline material reference guide trusted by hundreds of Engineers, Architects and Designers all over the World. The App was created to be a personal tool to help me take design decisions during the concept ideation of industrial products, in particular for 3D printing. Due to high demand, I decided to make it public and share it's information and power. Basically, it provides the fundamentals for most design/engineer materials on the market, based on reliable and curated academic sources. In addition, you can now create and manager your own Material, Resin or Filament data. Finally, the App features Apple Intelligence (AI) with a pair of Entity Masters in material engineering and STEM: HAL 9000 and Elemento, which can be accessed 24/7 while being on or offline (no internet). The guide contains material categories such as polymers, metals, naturals and more. All of these include synthetic, organic, bio-degradable, plastic, and much more subcategories. Each material contains information such as: About, Properties, Tags, Applications, Types and Photos. HAL 9000 & Elemento (AI entities): The legend of HAL is back. Ask anything from space to robotics or biology, HAL and Elemento are Gods of material engineering and science. HAL does precise flawless analysis while Elemento brings fresh human creativity with an attitude. In addition, you can choose the Tone of AI: Formal, Friendly, Direct or Arrogant. Both AI Entities work offline 24/7. Other features includes: • AI Chat with HAL 9000 or Elemento • Material Packs (subscribers) • 3D-model viewer/import/export • Object Capture: Scan Objects • Favorites section • Offline reference (no Internet needed) • Long list of properties per material • Save Notes per material/resin/filament • Create Designs using Apple Pencil • Support for all iPhone screen sizes • Dark Mode • iPadOS support • MacOS support • Continuous Updates with New Content • UNIVERSAL PURCHASE - One Payment for all Devices New Pro version auto-renew subscriptions: - 1 year (Gold) | 3 month (Silver) | 1 month (Bronze) subscriptions* - Access to all material database ABOUT SUBSCRIPTIONS • Payment will be charged to iTunes Account at confirmation of purchase. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period.

 • Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal.
 • Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase.
 • Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable. 

• Terms of use (EULA): https://www.termsfeed.com/live/faff17b4-8765-4690-b57e-9aabde3d2950

About

OptiListen

Enhance your listening abilities with this straightforward application. Track your progress during audio or video calls and build your skills over time. It's designed for anyone looking to improve their active listening.

Highlights
  • Set listening goals
  • Track session results
  • Build listening skills
  • Use with audio/video calls
  • Local data storage
Features
Read full description

OptiListen is an easy to use app, created by and for folks who would like to listen a little more. Put your headphones on, start a session, set a goal, and see how you do. With OptiListen, you can track your results over time, and build your listening skills, one audio or video call at a time. Note: We're launching OptiListen as a free app and all data is kept locally on your phone.

Screenshots

Design Materials4 screens
OptiListen4 screens

Verdict

The call

The clearest difference is rating: OptiListen at 5.0 against Design Materials's 4.5. OptiListen also leads on in-app purchases (none vs 3) and iOS requirement (11.0 vs 18.6). Design Materials's advantage is update cadence (every 3 months vs every 6 months). On price, ratings volume, ads 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. Design Materials sells 3 in-app purchases, starting at $7.99 per month. OptiListen asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

OptiListen holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 2 and 3 respectively.

UpkeepUpdate frequency

Design Materials ships an update every 3 months, OptiListen every 6 months. The most recent releases landed on October 18, 2026 and October 21, 2026 respectively.

Scorecard5 real differences · 5 level
Design Materials versus OptiListen: the parameters behind the verdict, then further details
ParameterDesign MaterialsOptiListen
PriceFreeFree
Rating4.5 (2 ratings)5.0 (3 ratings) — better
Positive reviews33.3% of reviews—
Number of ratings23 — better
Update frequencyEvery 3 months — betterEvery 6 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Mac — betteriPhone, iPod
Requires iOS18.611.0 — better
Further details — not scored
Size28 MB19 MB
Age rating4+4+
DeveloperChrystian EnriquezChristian Crumlish

Customer experience

Design Materials

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive33.3%
Neutral0.0%
Negative66.7%

OptiListen

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

3 purchases

Design Materials

Subscriptions3
  • Bronze member$7.991 Month
  • Silver member$17.993 Months
  • Gold member$49.991 Year
None

OptiListen

No in-app purchases

Questions

Is Design Materials free?
Design Materials is free to download, with in-app purchases available.
Is OptiListen free?
OptiListen is free to download, with no in-app purchases.
Which has better reviews, Design Materials or OptiListen?
OptiListen is rated higher. Design Materials averages 4.5 out of 5 from 2 ratings, while OptiListen averages 5.0 from 3 ratings.
Do Design Materials or OptiListen have ads?
Neither Design Materials nor OptiListen shows ads.
Which is updated more often, Design Materials or OptiListen?
Design Materials ships an update every 3 months, and OptiListen every 6 months. Most recently, Design Materials was updated on October 18, 2026 and OptiListen on October 21, 2026.

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