# Plumbing Formulator vs Drive Reminder

The clearest difference is update cadence: Drive Reminder at weekly against Plumbing Formulator's every 2 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Plumbing Formulator sells 4 one-off in-app purchases and Drive Reminder sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Plumbing Formulator ships an update every 2 months, Drive Reminder weekly. The most recent releases landed on October 6, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | Plumbing Formulator | Drive Reminder |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (7 ratings)](https://appshunter.io/ios/app/plumbing-formulator/id303497783/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 9.1% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | Free | — |
| Size | 123 MB | 4 MB |
| Requires iOS | 18.6 | **17.0** |
| Devices | iPhone, iPad | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Historycentral.com](https://appshunter.io/developer/1744330560) | [Ray Flinkerbusch](https://appshunter.io/developer/1785196542) |

## What reviewers say

### Plumbing Formulator

[App page](https://appshunter.io/ios/app/plumbing-formulator/id303497783)

This professional calculator app provides over 200 formulas, calculators, and reference materials for plumbers, HVAC technicians, and mechanical contractors. It covers a wide range of calculations for water flow, piping, drainage, water heaters, pumps, and more, all in one pocket-sized tool.

**Highlights:** Over 200 formulas and calculators, Water flow and supply calculations, Pipe and piping calculations, Drainage and venting calculations, Water heater and pump calculations, Reference charts and code books, Pipe cut list optimizer

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Version | $1.99 | one-time |
| Pro Purchase | $3.99 | one-time |
| Starter | $5.99 | one-time |
| Growth | $9.99 | one-time |


### Drive Reminder

[App page](https://appshunter.io/ios/app/drive-reminder/id6754190898)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Buy Me Coffee | $1.99 | one-time |
| Premium Pack - 2 Vehicles | $1.99 | one-time |
| Premium Pack - 6 Vehicles | $4.99 | one-time |


## Frequently asked questions

### Is Plumbing Formulator free?

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

### Is Drive Reminder free?

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

### Do Plumbing Formulator or Drive Reminder have ads?

Neither Plumbing Formulator nor Drive Reminder shows ads.

### Which is updated more often, Plumbing Formulator or Drive Reminder?

Plumbing Formulator ships an update every 2 months, and Drive Reminder weekly. Most recently, Plumbing Formulator was updated on October 6, 2026 and Drive Reminder on September 29, 2026.

---

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