# ULTRAPEN™ PTBTx™ vs Bluemax

ULTRAPEN™ PTBTx™ and Bluemax are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ULTRAPEN™ PTBTx™ ships an update every 5 months, Bluemax every 4 months. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | ULTRAPEN™ PTBTx™ | Bluemax |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/ultrapen-ptbtx/id885545007/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 4 months** |
| Monetization | Free | — |
| Size | 9 MB | 6 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Myron L Company](https://appshunter.io/developer/885545010) | [Cyclops Marine Ltd](https://appshunter.io/developer/1439465275) |

## What reviewers say

### ULTRAPEN™ PTBTx™

[App page](https://appshunter.io/ios/app/ultrapen-ptbtx/id885545007)

This application transforms your iOS device into a powerful water quality measurement tool when paired with specific pocket testers. It offers wireless data logging, calibration tracking, and exportable reports for various water parameters.

**Highlights:** Wireless communication with pocket testers, Intuitive GUI for pairing and calibration, On-board database for measurements, Data export in .xls, .xlsx, .csv formats, Automatic calibration records, Supports conductivity, TDS, salinity, pH, ORP, and temperature

**Features:** macOS Compatibility

**In-app purchases:** none


### Bluemax

[App page](https://appshunter.io/ios/app/bluemax/id6463031362)

**In-app purchases:** none


## Frequently asked questions

### Is ULTRAPEN™ PTBTx™ free?

ULTRAPEN™ PTBTx™ is free to download, with no in-app purchases.

### Is Bluemax free?

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

### Do ULTRAPEN™ PTBTx™ or Bluemax have ads?

Neither ULTRAPEN™ PTBTx™ nor Bluemax shows ads.

### Which is updated more often, ULTRAPEN™ PTBTx™ or Bluemax?

ULTRAPEN™ PTBTx™ ships an update every 5 months, and Bluemax every 4 months. Most recently, ULTRAPEN™ PTBTx™ was updated on October 24, 2026 and Bluemax on October 27, 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.*