# Oil density vs ESwap助理

The clearest difference is in-app purchases: ESwap助理 at none against Oil density's 2. ESwap助理 also leads on update cadence (monthly vs every 47 months) and iOS requirement (11.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Oil density sells 2 one-off in-app purchases. ESwap助理 asks for nothing beyond the download.

Oil density ships an update every 47 months, ESwap助理 monthly. The most recent releases landed on October 9, 2026 and September 11, 2026 respectively.

## The numbers

| Metric | Oil density | ESwap助理 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/oil-density/id1641733273/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 47 months | **Monthly** |
| Monetization | Free | — |
| Size | 7 MB | 46 MB |
| Requires iOS | 17.0 | **11.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [昆 张](https://appshunter.io/developer/517645105) | [Beijing Upsky Century Energy Storage Technology Co., LTD](https://appshunter.io/developer/1790395161) |

## What reviewers say

### Oil density

[App page](https://appshunter.io/ios/app/oil-density/id1641733273)

This tool calculates the standard density of oil products based on measured apparent density. It automatically queries density tables and computes volume correction factors for accurate standard volume and mass calculations. Improve efficiency and accuracy compared to manual methods.

**Highlights:** Calculates standard oil density, Queries petroleum density tables, Computes volume correction factor (VCF), Calculates standard volume and mass, Adheres to GB/T 1885-1998 national standard

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly card | $2.99 | one-time |
| Lifetime Card | $8.99 | one-time |


### ESwap助理

[App page](https://appshunter.io/ios/app/eswap/id6740604131)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Oil density free?

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

### Is ESwap助理 free?

ESwap助理 is free to download, with no in-app purchases.

### Do Oil density or ESwap助理 have ads?

Neither Oil density nor ESwap助理 shows ads.

### Which is updated more often, Oil density or ESwap助理?

Oil density ships an update every 47 months, and ESwap助理 monthly. Most recently, Oil density was updated on October 9, 2026 and ESwap助理 on September 11, 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.*