# uSpectrum MK350S vs Inbox Zero

The clearest difference is in-app purchases: uSpectrum MK350S at none against Inbox Zero's 2. uSpectrum MK350S also leads on iOS requirement (6.0 vs 18.0). Inbox Zero's advantage is update cadence (weekly vs every 2 months). On price, ads and device support there is nothing between them.

Both are free to download. Inbox Zero sells 2 in-app purchases, starting at $19.99 per month. uSpectrum MK350S asks for nothing beyond the download.

uSpectrum MK350S ships an update every 2 months, Inbox Zero weekly. The most recent releases landed on October 23, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | uSpectrum MK350S | Inbox Zero |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/uspectrum-mk350s/id718838051/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 33.3% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | **Free** | Subscription |
| Size | 54 MB | 35 MB |
| Requires iOS | **6.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [United Power Research Technology Corporation](https://appshunter.io/developer/1501316337) | [Inbox Zero Inc.](https://appshunter.io/developer/1880462164) |

## What reviewers say

### uSpectrum MK350S

[App page](https://appshunter.io/ios/app/uspectrum-mk350s/id718838051)

This app provides advanced light analysis and efficient workflow features for lighting production. It offers remote control operations, data storage, and detailed light readings including BIN ranking and CRI.

**Highlights:** WiFi remote control, SD card data storage, Basic and advanced light analytics, BIN ranking, Log compare, CRI (R1-R15)

**Features:** macOS Compatibility

**In-app purchases:** none


### Inbox Zero

[App page](https://appshunter.io/ios/app/inbox-zero-ai-email-assistant/id6759736561)

This email client offers a fast, offline-capable experience for Gmail and Outlook, featuring an AI assistant for managing your inbox. It allows for easy unsubscribing, smart inbox organization, and quick replies.

**Highlights:** AI email assistant, Offline access, Unsubscribe from senders, Split inbox by tabs, Quick swipe actions, Scheduled sending, Undo send

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Inbox Zero Starter Monthly | $19.99 | per month |
| Inbox Zero Starter Annual | $199.99 | per year |


## Frequently asked questions

### Is uSpectrum MK350S free?

uSpectrum MK350S is free to download, with no in-app purchases.

### Is Inbox Zero free?

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

### Do uSpectrum MK350S or Inbox Zero have ads?

Neither uSpectrum MK350S nor Inbox Zero shows ads.

### Which is updated more often, uSpectrum MK350S or Inbox Zero?

uSpectrum MK350S ships an update every 2 months, and Inbox Zero weekly. Most recently, uSpectrum MK350S was updated on October 23, 2026 and Inbox Zero on October 31, 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.*