ProMasters Only vs Shellie
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ProMasters Only
This app provides diagnostic tools and information specifically for Ram ProMaster vans. It offers real-time gauge monitoring, trouble code explanations, and a repair log, requiring a separate OBD dongle purchase.
- Trouble code reader with explanations
- Real-time gauge monitoring (Voltage, Oil Pressure, Coolant Temp, etc.)
- Transmission fluid temperature gauge
- Oil change and repair log book
- Repair shop finder
- Technical library with videos
- Fluids and consumables specifications
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Welcome to the ProMasters Only App version 2.0. This is a phone or tablet app written specifically for the Ram ProMaster. Covers Promaster 1500, 2500, and 3500 all years. App requires hardware purchase of an OBD dongle ($15-30 on Amazon). Approved dongles and links to them are in the demonstration video: https://youtu.be/XWhNLE6Peno New and Improved for 2.0: * Gauge Alarms * One-touch Login * Wake Lock * Heads Up Display Mode * Gauge explanation videos * Oil Change/Repair log book * Repair Shop Finder * Technical Library of videos covering ALL topics * Fluids and Consumables Specs This app features a trouble code reader, and if any of the common codes for ProMaster come up it provides a link for a detailed explanation of that code, what causes it, and how to fix it. Gauges for Voltage, Oil Pressure, Coolant Temperature, Engine power, and Fuel trims. Plus the ALL IMPORTANT Transmission fluid temperature gauge - monitoring transmission temps may save your transmission! Note: transmission temp gauge does not work on 2022-later vans, but is not as important on those newer transmissions. Note: app not fully implemented for the diesel ProMasters. App is free upgrades for life.
Shellie
This utility app assists RV owners in leveling their vehicles. It provides a simple interface to ensure your RV is perfectly balanced for comfort and stability.
- RV leveling assistance
- Vehicle balancing
- Simple interface
- Designed for Winnebago Travato
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Winnebago Travato Leveling Tool
Screenshots
Verdict
The clearest difference is price: Shellie at Free against ProMasters Only's $69.99. Shellie also leads on rating (5.0 vs 4.5) and update cadence (every 2 days vs every 7 months). ProMasters Only's advantage is ratings volume (21 vs 1) and chart position (#127 vs unranked). On ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Shellie is free to download; ProMasters Only costs $69.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Shellie holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: ProMasters Only has 21 ratings behind it against 1, so its average is the more settled of the two.
ProMasters Only ships an update every 7 months, Shellie every 2 days. The most recent releases landed on September 13, 2026 and June 1, 2026 respectively.
| Parameter | ProMasters Only | Shellie |
|---|---|---|
| Price | $69.99 | Free — better |
| Rating | 4.5 (21 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 78.6% of reviews | — |
| Number of ratings | 21 — better | 1 |
| Update frequency | Every 7 months | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Best chart rank | #127 — better | — |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 18.2 |
| Further details — not scored | ||
| Size | 27 MB | 3 MB |
| Age rating | 17+ | 4+ |
| Developer | Kip Amore | Peter Walker |
Customer experience
ProMasters Only
Shellie
In-app purchases
ProMasters Only
No in-app purchases
Shellie
No in-app purchases
