# Oil Sample Analysis vs Simple Invoice Maker

The clearest difference is in-app purchases: Oil Sample Analysis at none against Simple Invoice Maker's 6. Oil Sample Analysis also leads on ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Simple Invoice Maker sells 3 in-app purchases, starting at $6.99 per 7 days. Oil Sample Analysis asks for nothing beyond the download.

Oil Sample Analysis ships an update every 2 months, Simple Invoice Maker every 3 months. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Oil Sample Analysis | Simple Invoice Maker |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 2 months** | Every 3 months |
| Size | 41 MB | 72 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Shell Information Technology International B.V.](https://appshunter.io/developer/410842826) | [PAPYONLAB YAZILIM BILGI TEKNOLOJILERI TICARET LIMITED SIRKETI](https://appshunter.io/developer/1546900076) |

## What reviewers say

### Oil Sample Analysis

[App page](https://appshunter.io/ios/app/oil-sample-analysis/id1575505655)

**In-app purchases:** none


### Simple Invoice Maker

[App page](https://appshunter.io/ios/app/simple-invoice-maker-invoicer/id6670252344)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Invoice generator | $6.99 | per 7 days |
| Invoice generator | $11.99 | per month |
| Invoice generator | $59.99 | per year |


## Frequently asked questions

### Is Oil Sample Analysis free?

Oil Sample Analysis is free to download, with no in-app purchases.

### Is Simple Invoice Maker free?

Simple Invoice Maker is free to download, with in-app purchases available.

### Do Oil Sample Analysis or Simple Invoice Maker have ads?

Simple Invoice Maker shows ads; Oil Sample Analysis does not.

### Which is updated more often, Oil Sample Analysis or Simple Invoice Maker?

Oil Sample Analysis ships an update every 2 months, and Simple Invoice Maker every 3 months. Most recently, Oil Sample Analysis was updated on November 3, 2026 and Simple Invoice Maker on November 4, 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.*