# True Proof vs SpotElectric

The clearest difference is price: SpotElectric at Free against True Proof's $9.99. SpotElectric also leads on update cadence (every 2 weeks vs every 4 months). True Proof's advantage is in-app purchases (none vs 2). On ads, device support and iOS requirement there is nothing between them.

SpotElectric is free to download; True Proof costs $9.99 up front. SpotElectric sells 2 in-app purchases, starting at $2.99 per month. True Proof asks for nothing beyond the download.

True Proof ships an update every 4 months, SpotElectric every 2 weeks. The most recent releases landed on September 12, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | True Proof | SpotElectric |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[4.0 (4 ratings)](https://appshunter.io/ios/app/true-proof/id901015790/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 weeks** |
| Monetization | Paid | — |
| Size | 8 MB | 32 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Greg Miller](https://appshunter.io/developer/901015793) | [Ludek Bartos](https://appshunter.io/developer/1892645891) |

## What reviewers say

### True Proof

[App page](https://appshunter.io/ios/app/true-proof/id901015790)

This app calculates the true proof of water-alcohol mixtures based on hydrometer readings and temperature. It also performs gauging calculations and dilutions, accounting for temperature-dependent mixing. Results can be logged, annotated, and emailed for record-keeping.

**Highlights:** True proof calculation, Gauging calculations, Dilution calculations, Temperature compensation, Log and email results, Multiple unit support

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

**In-app purchases:** none


### SpotElectric

[App page](https://appshunter.io/ios/app/spotelectric/id6762044102)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SpotElectric Premium | $2.99 | per month |
| SpotElectric Premium | $24.99 | per year |


## Frequently asked questions

### Is True Proof free?

True Proof costs $9.99, with no in-app purchases.

### Is SpotElectric free?

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

### Do True Proof or SpotElectric have ads?

Neither True Proof nor SpotElectric shows ads.

### Which is updated more often, True Proof or SpotElectric?

True Proof ships an update every 4 months, and SpotElectric every 2 weeks. Most recently, True Proof was updated on September 12, 2026 and SpotElectric on September 8, 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.*