# Aika ERP vs # Simple Invoice

The clearest difference is in-app purchases: Aika ERP at none against # Simple Invoice's 2. Aika ERP also leads on update cadence (every 4 days vs every 8 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. # Simple Invoice sells 2 in-app purchases, starting at $1.99 per month. Aika ERP asks for nothing beyond the download.

Aika ERP ships an update every 4 days, # Simple Invoice every 8 days. The most recent releases landed on October 24, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Aika ERP | # Simple Invoice |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 8 days |
| Size | 30 MB | 48 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [AIKA TEKNOLOJI](https://appshunter.io/developer/1878502304) | [YUKI TANAIKE](https://appshunter.io/developer/478558546) |

## What reviewers say

### Aika ERP

[App page](https://appshunter.io/ios/app/aika-erp/id6759445322)

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

**In-app purchases:** none


### # Simple Invoice

[App page](https://appshunter.io/ios/app/simple-invoice/id6761528129)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Invoice Pro (Monthly) | $1.99 | per month |
| Invoice Pro (Annual) | $18.00 | per year |


## Frequently asked questions

### Is Aika ERP free?

Aika ERP is free to download, with no in-app purchases.

### Is # Simple Invoice free?

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

### Do Aika ERP or # Simple Invoice have ads?

Neither Aika ERP nor # Simple Invoice shows ads.

### Which is updated more often, Aika ERP or # Simple Invoice?

Aika ERP ships an update every 4 days, and # Simple Invoice every 8 days. Most recently, Aika ERP was updated on October 24, 2026 and # Simple Invoice on October 18, 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.*