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Best Diagnostic Apps

250+ iOS apps curated and reviewed

4.6 avg rating
20 free apps
Updated September 2026

Every iPhone needs a few good diagnostic apps. We benchmark 250+ of them on App Store rating, freshness, and pricing, then surface the standouts so you don't have to scroll the App Store yourself.

Compare top Diagnostic Apps (September 2026)

#AppPriceRatingAdsIn-App PurchasesUpdated
1Apple SupportApple SupportFree3.9★ (33K)NoYesSep 2026
2Phone DiagnosticsPhone DiagnosticsFree3.8★ (86)NoYesAug 2026
3Device Monitor²Device Monitor²Free4.7★ (9.2K)NoYesSep 2026
4Car Scanner ELM OBD2Car Scanner ELM OBD2Free4.8★ (32K)YesYesSep 2026
5Phone Doctor PlusPhone Doctor PlusFree4.4★ (328)YesNoAug 2026
6RepairSolutions2RepairSolutions2Free4.8★ (37K)NoYesSep 2026
7OBD2 Scanner | OBD Auto DoctorOBD2 Scanner | OBD Auto DoctorFree4.4★ (6.1K)NoYesAug 2026
8Car Scanner: OBD DiagnosticCar Scanner: OBD DiagnosticFree—NoYesJul 2026

Top Picks for Diagnostic

Apple Support#1

Apple Support by Apple

We’re here to help
Editor's Choice
🔧 Utilities
3.9😐(33K ratings)
Free
Apple Support screenshot 1
Apple Support screenshot 2
Apple Support screenshot 3
Apple Support screenshot 4

Access personalized solutions for all your Apple products and services in one convenient app. Troubleshoot issues with guided steps, chat with support, manage subscriptions, reset passwords, and find nearby service locations for Genius Bar appointments.

What We Love

  • 👍 Helpful and friendly support staff
  • 🚀 Quick response and resolution of issues
  • 💡 Useful troubleshooting features
  • 🔒 Secure and trustworthy service

Room to Improve

  • 🐛 Buggy and unreliable app performance
  • 🤖 Lack of knowledgeable support staff
  • ⏱️ Long wait times and repeated transfers
Phone Diagnostics#2

Phone Diagnostics by HITEK_NOVA

Test & Find Repair Shop
Strong Contender
🔧 Utilities
3.8(86 ratings)
FreeIn-App Purchases
Phone Diagnostics screenshot 1
Phone Diagnostics screenshot 2
Phone Diagnostics screenshot 3
Phone Diagnostics screenshot 4
Phone Diagnostics screenshot 5
Phone Diagnostics screenshot 6

Easily test and check all mobile device functionalities. This app is useful before purchasing a device, sending it for repair, or after receiving it back. It also helps you locate nearby repair shops.

Device Monitor²#3

Device Monitor² by Fast-Devs Project

System activity info
Worth Considering
🛠️ Developer Tools
4.7😊(9.2K ratings)
FreeIn-App Purchases
#40in Developer Tools
Device Monitor² screenshot 1
Device Monitor² screenshot 2
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Device Monitor² screenshot 4
Device Monitor² screenshot 5
Device Monitor² screenshot 6

This app provides comprehensive system activity information for Apple devices, including detailed insights into hardware, sensors, and network status. It offers privacy controls, customizable widgets, and advanced testing and reporting features through optional in-app purchases.

What We Love

  • 🚀 Effective RAM cleaning
  • 🔍 Detailed device information
  • 🔧 Useful toolkit features
  • 💰 Fair one-time pricing

Room to Improve

  • 🐛 RAM cleaning issues after updates
  • 🔌 High background battery usage
  • 🕰️ Slow RAM cleaning process

More Diagnostic apps to explore

4
Car Scanner ELM OBD2
Car Scanner ELM OBD2
Car Scanner ELM OBD2
The best OBD2 diagnostic tool!
Free

Monitor your car's performance, diagnose engine issues, and view sensor data in real-time. Customize your dashboard with gauges and charts, and reset fault codes. Supports a wide range of vehicles and offers advanced features for specific car brands.

Real-time sensor dataOBD fault code reading and resettingCustomizable dashboard with gauges
🔧 Utilities
(32K)
free with in-app purchases
5
Phone Doctor Plus
Phone Doctor Plus
Phone Doctor Plus
by Idea Mobile Tech inc.
Free

Diagnose over 40 hardware and system issues with this app. Monitor your phone's hardware, battery, memory, and storage. Track network usage and daily charging cycles to keep your device running smoothly.

40+ hardware diagnostic testsSystem monitoring (hardware, battery, memory, storage)Daily battery capacity and charging cycle recording
🔧 Utilities
(328)
ad-supported
6
RepairSolutions2
RepairSolutions2
RepairSolutions2
by Innova Electronic
Free

This app provides comprehensive vehicle care and repair information for car and truck owners, DIYers, and technicians. It offers diagnostic capabilities with compatible OBD2 scanners and a vast database of verified fixes from ASE Master Technicians. Users can also access free vehicle maintenance information and schedule repairs.

OBD2 scanner integrationVerified repair databaseDiagnostic trouble code definitions
🔧 Utilities
(37K)
free with in-app purchases
7
OBD2 Scanner | OBD Auto Doctor
OBD2 Scanner | OBD Auto Doctor
OBD2 Scanner | OBD Auto Doctor
Car Diagnostics & Check Engine
Free

Diagnose your car's engine light issues and monitor real-time performance data. This app allows you to read and clear diagnostic trouble codes, track fuel consumption, and view sensor data. It's a comprehensive tool for understanding your vehicle's health.

Read and clear OBD2 diagnostic trouble codes (DTC)Reset Check Engine LightMonitor real-time vehicle data and sensor readings
🔧 Utilities
(6.1K)
free with in-app purchases
8
Car Scanner: OBD Diagnostic
Car Scanner: OBD Diagnostic
Car Scanner: OBD Diagnostic
OBD2 Auto Doctor App, ELM327
Free
🔧 Utilities
(0)
9
iDiagnostic
iDiagnostic
iDiagnostic
Hardware Diagnostic Tool
Free

This tool helps you quickly check the functionality of your iPhone or iPad's hardware components. It tests the display, touch screen, cameras, speakers, and microphone, ensuring everything is working as expected. Designed for privacy, all tests are performed on-device with no data collection.

Display color and dead pixel testConfigurable touch screen grid testCamera detection and individual testing
🔧 Utilities
(1)
free
10
ATF Diagnostic
ATF Diagnostic
ATF Diagnostic
ATF
Free
🏥 Medical
(0)
11
BLE Diagnostic Tool
BLE Diagnostic Tool
BLE Diagnostic Tool
BLE Diagnostic Tool
Free

Connect to devices via Bluetooth to retrieve and display diagnostic data. Analyze information obtained through the protocol to troubleshoot and understand device status.

Bluetooth connectivityData retrievalProtocol analysis
🔧 Utilities
(1)
free
12
M-JET Diagnostic
M-JET Diagnostic
M-JET Diagnostic
BRP Vehicle Diagnostic Tool
Free
🔧 Utilities
(0)
13
PingKit - Network Tools
PingKit - Network Tools
PingKit - Network Tools
WiFi Speed Test & Analyzer
Free

Understand your home network with AI-powered explanations and 19 free tools. Identify devices, test speeds, and monitor connections privately on your iPhone. Offers advanced features and monitoring through optional subscriptions.

On-device AI for network explanations19 professional-grade network toolsSiri and Shortcuts integration
🔧 Utilities
(1)
free with in-app purchases
14
Car Scanner: OBD2 ELM Reader
Car Scanner: OBD2 ELM Reader
Car Scanner: OBD2 ELM Reader
OBD diagnostics for ELM327
Free

Transform your smartphone into a car diagnostic tool. Read and clear trouble codes, monitor real-time engine data, and access manufacturer-specific information. Analyze driving behavior and track fuel efficiency.

Read and clear OBD2 trouble codesReal-time car data monitoringManufacturer-specific code access
🔧 Utilities
(2)
freemium
15
iChecker: Phone Diagnostics
iChecker: Phone Diagnostics
iChecker: Phone Diagnostics
Battery Health & System Status
Free

This app performs comprehensive hardware diagnostics on your iPhone, checking 39 critical components. It provides an overall health grade and detailed test results, helping you identify potential issues before they become costly repairs. Generate shareable reports and monitor your device's health over time with routine checks.

39 forensic hardware testsInstant overall health gradeScreen and display checks
🔧 Utilities
(8)
free
16
Autmet | OBD2 Scanner
Autmet | OBD2 Scanner
Autmet | OBD2 Scanner
OBD2 scanner & car diagnostic
Free

This diagnostic tool connects to your vehicle's OBD data via a Bluetooth device. It allows you to read various ECU data and supports common OBD-II protocols.

Reads vehicle ECU dataBluetooth OBD device compatibleSupports OBD-II protocols
🔧 Utilities
(1)
free
17
System Status: hw monitor
System Status: hw monitor
System Status: hw monitor
CPU,battery,disk usage info
Free

Monitor your device's core performance metrics with this utility app. It provides real-time information on battery status, disk usage, CPU load, and network connections. Customize your view with light or dark themes and receive instant updates on system changes.

Graphical battery level displayDisk usage monitoringReal-time CPU usage
🔧 Utilities
(2.5K)
ad-supported
18
MyQuest for Patients
MyQuest for Patients
MyQuest for Patients
by Quest Diagnostics, Inc.
Free

Access your lab results, schedule appointments, and manage your health information securely. Find nearby locations, share data with providers, and even purchase your own tests. Take proactive control of your well-being.

View lab results securelyFind nearby Quest locationsSchedule and manage appointments
🏥 Medical
(466K)
free
19
RedlineAi: AI OBD Diagnostics
RedlineAi: AI OBD Diagnostics
RedlineAi: AI OBD Diagnostics
AI OBD scanner & diagnostics
Free

This app transforms your phone into a professional OBD-II scanner, providing AI-powered explanations for check-engine lights, repair cost estimates, and DIY repair guides. It also includes a recall checker and a vehicle maintenance tracker.

AI-powered OBD-II diagnosticsRepair cost estimatesDIY repair guides
🔧 Utilities
(2)
free with in-app purchases
20
UstaScan
UstaScan
UstaScan
تشخيص سيارتك بالذكاء الاصطناعي
Free
🔧 Utilities
(0)

FAQ about Diagnostic

What are the best diagnostic apps for iPhone?
Apple Support tops our diagnostic apps ranking as of September 2026, with a 3.9-star average from 33K App Store ratings, and it's free to download.
Yes — 20 of the top diagnostic apps we rank are free to download, including Apple Support and Phone Diagnostics.
Apple Support has no ads and offers in-app purchases, according to its App Store listing as of September 2026.
We track 250+ diagnostic apps on the iOS App Store as of September 2026, ranked by rating, recency, and analysis of real user reviews.
The Apple Support app provides personalized solutions for all your Apple products and services. You can learn how to manage subscriptions, reset your Apple Account password, troubleshoot issues with guided steps, chat with support, and find nearby locations to book Genius Bar or Apple Authorized Service Provider appointments.
No, you are not required to purchase an AppleCare+ plan to use the Apple Support app. The app is available to all Apple product owners seeking support, regardless of whether they have an AppleCare+ plan.

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