# Etalvis vs Backflow Tester Exam Prep

The clearest difference is iOS requirement: Etalvis at 15.1 against Backflow Tester Exam Prep's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Etalvis sells 1 one-off in-app purchase and Backflow Tester Exam Prep sells 3 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

Etalvis ships an update every 4 months, Backflow Tester Exam Prep every 3 months. The most recent releases landed on October 18, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Etalvis | Backflow Tester Exam Prep |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 months** |
| Size | 52 MB | 6 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [TagMango Inc](https://appshunter.io/developer/1611765353) | [Deeun Inc.](https://appshunter.io/developer/1691824695) |

## What reviewers say

### Etalvis

[App page](https://appshunter.io/ios/app/etalvis/id6746702257)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| The Learning Journey | $14.99 | one-time |


### Backflow Tester Exam Prep

[App page](https://appshunter.io/ios/app/backflow-tester-exam-prep/id6760266860)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Backflow Tester Pro - Monthly | $9.99 | per month |
| Annual Access | $24.99 | per year |
| Pro - Lifetime Access | $39.99 | one-time |


## Frequently asked questions

### Is Etalvis free?

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

### Is Backflow Tester Exam Prep free?

Backflow Tester Exam Prep is free to download, with in-app purchases available.

### Do Etalvis or Backflow Tester Exam Prep have ads?

Neither Etalvis nor Backflow Tester Exam Prep shows ads.

### Which is updated more often, Etalvis or Backflow Tester Exam Prep?

Etalvis ships an update every 4 months, and Backflow Tester Exam Prep every 3 months. Most recently, Etalvis was updated on October 18, 2026 and Backflow Tester Exam Prep on October 7, 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.*