# SAILS Mobile vs Build Fluency

The clearest difference is review sentiment: Build Fluency at 100% against SAILS Mobile's 15%. Build Fluency also leads on rating (5.0 vs 2.5) and update cadence (every 6 days vs every 4 months). SAILS Mobile's advantage is in-app purchases (none vs 5) and ratings volume (41 vs 1). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Build Fluency sells 5 one-off in-app purchases. SAILS Mobile asks for nothing beyond the download.

Build Fluency holds the better App Store score, 5.0 against 2.5. That said, the two scores are not equally well evidenced: SAILS Mobile has 41 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 15% of SAILS Mobile's written reviews are positive against 100% of Build Fluency's.

SAILS Mobile ships an update every 4 months, Build Fluency every 6 days. The most recent releases landed on August 11, 2026 and September 13, 2026 respectively.

## The numbers

| Metric | SAILS Mobile | Build Fluency |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.5 (41 ratings)](https://appshunter.io/ios/app/sails-mobile/id928540707/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/build-fluency/id6762920359/reviews)** |
| Number of ratings | **41** | 1 |
| Positive reviews | 15.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 6 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 50 MB | 11 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [S.A.I.L.S., INCORPORATED](https://appshunter.io/developer/1451095101) | [FOHBOH IO LLC](https://appshunter.io/developer/1793382540) |

## What reviewers say

### SAILS Mobile

[App page](https://appshunter.io/ios/app/sails-mobile/id928540707)

Access the SAILS Library Network from your iOS device. Search the catalog, manage your account, place holds, and pay fines. You can even scan item barcodes to find available copies.

**Highlights:** Search library catalog, Manage user account, Place holds on items, Pay fines with credit card, Scan item barcodes

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

**In-app purchases:** none


### Build Fluency

[App page](https://appshunter.io/ios/app/build-fluency/id6762920359)

This app helps you move beyond simple recognition of information to true understanding. Practice explaining concepts in your own words, either by writing or speaking, to build mental maps and strengthen recall. It's designed to help you think more clearly and speak with greater confidence.

**Highlights:** Practice explaining concepts, Written or spoken responses, Structured feedback, Build mental maps of subjects, Strengthen knowledge recall, Develop connected understanding

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Economics | $9.99 | one-time |
| Unlock Game Theory | $9.99 | one-time |
| Unlock Political Thought | $9.99 | one-time |
| Unlock Psychology | $9.99 | one-time |
| Unlock Western Philosophy | $9.99 | one-time |


## Frequently asked questions

### Is SAILS Mobile free?

SAILS Mobile is free to download, with no in-app purchases.

### Is Build Fluency free?

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

### Which has better reviews, SAILS Mobile or Build Fluency?

Build Fluency is rated higher. SAILS Mobile averages 2.5 out of 5 from 41 ratings, while Build Fluency averages 5.0 from 1 ratings.

### Do SAILS Mobile or Build Fluency have ads?

Neither SAILS Mobile nor Build Fluency shows ads.

### Which is updated more often, SAILS Mobile or Build Fluency?

SAILS Mobile ships an update every 4 months, and Build Fluency every 6 days. Most recently, SAILS Mobile was updated on August 11, 2026 and Build Fluency on September 13, 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.*