# iSilo vs OptimalWork

The clearest difference is review sentiment: OptimalWork at 100% against iSilo's 51%. OptimalWork also leads on price (Free vs $9.99) and rating (4.8 vs 3.8). iSilo's advantage is in-app purchases (none vs 8) and chart position (#115 vs unranked). On ratings volume, update cadence, ads and device support there is nothing between them.

OptimalWork is free to download; iSilo costs $9.99 up front. OptimalWork sells 8 in-app purchases, starting at $18.95 per month. iSilo asks for nothing beyond the download.

OptimalWork holds the better App Store score, 4.8 against 3.8. Both are backed by a comparable volume of ratings — 50 and 19 respectively. Written reviews point the same way: 51% of iSilo's written reviews are positive against 100% of OptimalWork's.

iSilo ships an update every 3 weeks, OptimalWork fortnightly. The most recent releases landed on September 28, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | iSilo | OptimalWork |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [3.8 (50 ratings)](https://appshunter.io/ios/app/isilo/id284979163/reviews) | **[4.8 (19 ratings)](https://appshunter.io/ios/app/optimalwork/id6475370841/reviews)** |
| Number of ratings | **50** | 19 |
| Positive reviews | 50.6% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Fortnightly** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#115** | — |
| Size | 13 MB | 82 MB |
| Requires iOS | **8.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [DC & Co.](https://appshunter.io/developer/284947607) | [OptimalWork](https://appshunter.io/developer/1724082187) |

## What reviewers say

### iSilo

[App page](https://appshunter.io/ios/app/isilo/id284979163)

**Currently charting:** #115 Top Paid · Productivity (US App Store)

Read various document formats including iSilo, Palm Doc, and plain text. Access a vast library of content, organize your files, and customize viewing options for a personalized reading experience. Transfer documents easily via USB, Wi-Fi, or web download.

**Highlights:** Supports iSilo, Palm Doc, and plain text formats, Extensive document library and creation tools, Organize documents with categories and favorites, Customizable viewing options (font, colors, themes), Autoscroll, full-screen, and orientation support, Text search, copy, and annotation, Multiple document transfer methods (USB, Wi-Fi, Web)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💻 Works well with Christian books
- 📚 Excellent for reading documents with embedded hyperlinks
- ⚡ Fast and smooth on many devices
- 🙌 Hands down a life-saving app
- 🏆 Basic but wonderful functionality

**What reviewers complain about**

- 🐛 Crashes upon opening
- 🐛 Unable to download new material since 2017
- 🐛 Crashes when trying to open code-protected file
- 🐛 Scrolling issues and performance problems
- 🤖 Outdated and abandoned by developers

**Reported bugs**

- Crashes when trying to open certain file formats
- Displaying issues with Palm format (PDB) files
- Inability to download files from Dropbox
- Text going off-screen after recent updates
- Bookmarks and annotations not syncing across devices

**Requested features**

- Add dark mode feature
- Improve text highlighting and annotation capabilities
- Implement cloud sync and cross-device support
- Modernize the user interface
- Add support for iOS Files app


### OptimalWork

[App page](https://appshunter.io/ios/app/optimalwork/id6475370841)

This app helps you overcome procrastination, anxiety, and distraction by applying a new psychology of growth to your daily work. Achieve new heights of productivity, focus, and skill by approaching challenges as opportunities for profound development.

**Highlights:** Psychology of growth approach, Overcome procrastination, Reduce anxiety and distraction, Enhance productivity and focus, Skill development, Daily work application

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic - Student Monthly | $18.95 | per month |
| Basic - Monthly | $24.95 | per month |
| Premium - Student Monthly | $35.95 | per month |
| Premium - Monthly | $49.95 | per month |
| Basic - Student Yearly | $149.99 | per year |
| Basic - Yearly | $199.99 | per year |
| Premium - Student Yearly | $274.99 | per year |
| Premium - Yearly | $359.99 | per year |


## Frequently asked questions

### Is iSilo free?

iSilo costs $9.99, with no in-app purchases.

### Is OptimalWork free?

OptimalWork is free to download, with in-app purchases available.

### Which has better reviews, iSilo or OptimalWork?

OptimalWork is rated higher. iSilo averages 3.8 out of 5 from 50 ratings, while OptimalWork averages 4.8 from 19 ratings.

### Do iSilo or OptimalWork have ads?

Neither iSilo nor OptimalWork shows ads.

### Which is updated more often, iSilo or OptimalWork?

iSilo ships an update every 3 weeks, and OptimalWork fortnightly. Most recently, iSilo was updated on September 28, 2026 and OptimalWork on September 21, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*