# Spark vs First Due Mobile

The clearest difference is review sentiment: Spark at 75% against First Due Mobile's 0%. Spark also leads on rating (4.8 vs 1.6) and ratings volume (7.5K vs 10). First Due Mobile's advantage is in-app purchases (none vs 2). On price, ads and device support there is nothing between them.

Both are free to download. Spark sells 2 one-off in-app purchases. First Due Mobile asks for nothing beyond the download.

Spark holds the better App Store score, 4.8 against 1.6. That said, the two scores are not equally well evidenced: Spark has 7.5K ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 75% of Spark's written reviews are positive against 0% of First Due Mobile's.

Spark ships an update every 5 weeks, First Due Mobile every 7 months. The most recent releases landed on October 22, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Spark | First Due Mobile |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (7.5K ratings)](https://appshunter.io/ios/app/spark-shift-calendar/id390915382/reviews)** | [1.6 (10 ratings)](https://appshunter.io/ios/app/first-due-mobile-fedramp/id6670145457/reviews) |
| Number of ratings | **7.5K** | 10 |
| Positive reviews | **74.8% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 7 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 10 MB | 224 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [E.L.K. Equities LLC](https://appshunter.io/developer/1775442602) | [Locality Media, Inc.](https://appshunter.io/developer/1355085433) |

## What reviewers say

### Spark

[App page](https://appshunter.io/ios/app/spark-shift-calendar/id390915382)

This app simplifies shift work for professionals like first responders and healthcare workers. It offers full customization, secure cloud syncing, and streamlined shift trading. Plan your life and stay organized with instant visual cues and reliable support.

**Highlights:** Full shift customization, Secure cloud sync, Streamlined shift trades, Instant visual cues, Comprehensive shift coverage, User-friendly interface

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription Renewal | $0.99 | one-time |
| Initial Annual Subscription | $5.99 | one-time |

**What reviewers like**

- 🚀 Excellent calendar app
- 👍 Easy to use and set up
- 🔒 Secure and reliable
- 💡 Customizable and feature-rich
- 👍 Great for shift work and emergency services

**What reviewers complain about**

- 🐛 Occasional crashes and bugs
- 💰 Subscription model and pricing issues
- 🔧 Needs more frequent updates
- 🔧 Compatibility issues with newer devices
- 🔧 Lack of certain features (e.g., widgets, dark mode)

**Reported bugs**

- Login and authentication problems
- Data loss and sync issues after updates
- Unreliable performance on some devices

**Requested features**

- Ability to sync with more calendar services
- More customization options
- Improved user interface and design
- Ability to view past schedules and events


### First Due Mobile

[App page](https://appshunter.io/ios/app/first-due-mobile-fedramp/id6670145457)

Receive instant incident notifications and navigate emergency scenes with advanced routing. Access integrated building data, pre-plans, and real-time unit tracking for enhanced situational awareness and team communication.

**Highlights:** Incident tracking and notification, Emergency response routing, Integrated building data, Pre-incident planning and mapping, Team chat and communication, Live unit tracking

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

**In-app purchases:** none


## Frequently asked questions

### Is Spark free?

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

### Is First Due Mobile free?

First Due Mobile is free to download, with no in-app purchases.

### Which has better reviews, Spark or First Due Mobile?

Spark is rated higher. Spark averages 4.8 out of 5 from 7.5K ratings, while First Due Mobile averages 1.6 from 10 ratings.

### Do Spark or First Due Mobile have ads?

Neither Spark nor First Due Mobile shows ads.

### Which is updated more often, Spark or First Due Mobile?

Spark ships an update every 5 weeks, and First Due Mobile every 7 months. Most recently, Spark was updated on October 22, 2026 and First Due Mobile on October 24, 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.*