# Polismart vs Let's Build Countdowns

The clearest difference is in-app purchases: Polismart at none against Let's Build Countdowns's 1. Polismart also leads on iOS requirement (13.0 vs 17.0). Let's Build Countdowns's advantage is update cadence (every 8 days vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. Let's Build Countdowns sells 1 one-off in-app purchase. Polismart asks for nothing beyond the download.

Polismart ships an update every 4 months, Let's Build Countdowns every 8 days. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Polismart | Let's Build Countdowns |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (2 ratings)](https://appshunter.io/ios/app/polismart/id510678959/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 8 days** |
| Monetization | Free | — |
| Size | 22 MB | 2 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Polimaster Inc.](https://appshunter.io/developer/510024237) | [Brian Leary](https://appshunter.io/developer/1869693110) |

## What reviewers say

### Polismart

[App page](https://appshunter.io/ios/app/polismart/id510678959)

This app monitors and controls radiation levels using compatible devices. It provides real-time data, alerts for exceeding thresholds, and various operational modes for users to understand and manage radiation exposure.

**Highlights:** Radiation control and monitoring, Compatible with Polimaster detectors, Real-time radiation level measurement, Threshold exceeded alerts, Dashboard, Track, History, World Map modes, User-friendly operation

**Features:** macOS Compatibility

**In-app purchases:** none


### Let's Build Countdowns

[App page](https://appshunter.io/ios/app/lets-build-countdowns/id6777798794)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Countdown Plus | $2.99 | one-time |


## Frequently asked questions

### Is Polismart free?

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

### Is Let's Build Countdowns free?

Let's Build Countdowns is free to download, with in-app purchases available.

### Do Polismart or Let's Build Countdowns have ads?

Neither Polismart nor Let's Build Countdowns shows ads.

### Which is updated more often, Polismart or Let's Build Countdowns?

Polismart ships an update every 4 months, and Let's Build Countdowns every 8 days. Most recently, Polismart was updated on October 23, 2026 and Let's Build Countdowns on October 24, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*