J1939OBD vs Gretio
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
J1939OBD
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A diagnostic app for industrial and commercial vehicle engines using the J1939 CAN protocol. The app supports the following functions: - Display the active error codes - Display the passive error codes - Delete the error codes - Display of engine measured values - Information about the status DPF - Information about the SCR system - Information about fuel consumption - Engine information - Terminal mode To connect to the engine you need an EML327 compatible Wifi OBD interface as of V1.4 and a connection cable from the diagnostic connector to OBD. Various manufacturers offer corresponding cables, as well as a well-known engine manufacturer from Cologne, who distributes a corresponding adapter cable via his dealer network. Visit my homepage for further informations. An EML327 Wifi interface is offered on known Internet platforms.
Gretio
This app enables advanced vehicle diagnostics and service functions for General Motors vehicles using an OBDLINK MX+ device. It analyzes data points, looks up trouble codes, and performs service procedures like DPF regenerations.
- Advanced diagnostic functions
- Analyze thousands of data points
- Look up diagnostic trouble codes
- Perform advanced service functions
- Exclusive for General Motors vehicles
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Use Gretio with an OBDLINK MX+ to perform advanced diagnostic functions on your diesel, gas, electric, or hybrid vehicle. Analyze thousands of different data points at high speeds. Look up diagnostic trouble codes for all modules including the Engine Control Module, Chassis Control Module, Drive Motor Control Modules, Battery Energy Control modules, Body Control Module, Radio, and many more. Perform advanced service functions such as diesel particulate filter service regenerations, selective catalytic reduction tests, power relay tests, and even program some features. Gretio is an advanced tool made for the DIY market. All procedures must be used in accordance with the vehicle's service manual or other OEM approved literature. Gretio is made exclusively for General Motors vehicles. Additional models will be supported in the future.
Screenshots
Verdict
The clearest difference is update cadence: Gretio at every 3 weeks against J1939OBD's every 41 months. J1939OBD's advantage is iOS requirement (12.1 vs 18.0). On price, ads, in-app purchases and device support 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
Both are free to download. J1939OBD sells 1 one-off in-app purchase and Gretio sells 4 in-app purchases, starting at $19.99 per year. Whichever you choose, the download price is not the number that matters.
J1939OBD ships an update every 41 months, Gretio every 3 weeks. The most recent releases landed on May 17, 2026 and August 15, 2026 respectively.
| Parameter | J1939OBD | Gretio |
|---|---|---|
| Price | Free | Free |
| Rating | — | 3.9 (22 ratings) — better |
| Positive reviews | — | 72.2% of reviews |
| Number of ratings | — | 22 — better |
| Update frequency | Every 41 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 12.1 — better | 18.0 |
| Further details — not scored | ||
| Size | 14 MB | 40 MB |
| Age rating | 4+ | 4+ |
| Developer | S.Koepge | Surreal Development LLC |
In-app purchases
J1939OBD
- Get full access for 1939OBD$3.99
Gretio
- Gretio All Access$19.991 Year
- Gretio RPO Pack 1$29.99
- Gretio RPO Pack 2$29.99
- RPO Pack 3$29.99









