iOS offers many third-party applications with over 2 million from which to choose. Many of these applications are designed to assist individuals with disabilities.
RAZ Mobility has compiled and presents many of the best accessibility applications available in the App Store*. The applications are grouped disability type and include a brief description.
The selection is based on the value of application features for individuals with disabilities, the overall user experience and reliability.
A great option for exploring accessibility applications is the RAZ Mobility Accessible Application Installer. The app offers a user-friendly selection tool based on type of disability allowing users to easily find and install helpful applications.
This section provides information about third-party applications. To see more info about Android built-in accessibility features, click the button below.
HEARING

Ava – 24/7 Accessible Life
An app that facilitates 2-way communication between deaf and hearing people who don’t know sign language. The app provides 24/7 real-time captioning (with up to 95% accuracy, based on artificial intelligence), on their smartphone.
Developer: Transcense, Inc.

CaptionMate
CaptionMate is a free service for individuals with hearing loss. It allows you to read both sides of the phone conversation instantaneously. CaptionMate works on smartphones, tablets, and all other phones, even your landline. Registration is free and creates no obligation.
Developer: Clarity Products LLC

GalaPro
GalaPro has created a digital solution for live shows providing subtitles, dubbing and amplification to the user's own mobile device. Our multilingual app provides access all over the world to theaters, opera, cinemas, conferences and live shows.
Developer: Gala Prompter Ltd

Note Listen for Deaf
Speech to text translation for deaf people, allowing a deaf person to write a note for a hearing person. This note will be displayed in large type and will be clearly visible on the device screen. This application allows a deaf person to talk with a hearing person, passing the phone to each other.
Developer: Vasily kiryakov

Spread The Sign – The Sign Language Dictionary
World’s largest sign language dictionary with over 200 000 signs! Learn American, Czech, British, Estonian, French, German, Austrian, Italian, Japanese, Latvian, Lithuanian, Polish, Portuguese, Brazilian, Romanian, Russian, Spanish, Swedish, and Turkish sign language.
Developer: Europeiskt Teckenspråkcenter
VISION

Eye-D Pro
Eye-D helps visually impaired be location aware, explore and navigate to nearby places of interest, evaluate surroundings with their smartphone camera and read printed text. Similar to free version of the Eye-D application but without advertisements and with some additional features.
Developer: GingerMind Technologies

The Google app keeps you in the know about the things you care about. Set up and use voice commands in Google Assistant. Find quick answers, explore your interests, and get a feed of stories and updates on topics that matter to you. The more you use the Google app, the better it gets.
Developer: Google LLC

KNFB Reader
KNFB Reader 3.0 is a rapid and efficient text recognition app. Its text-to-speech, text-to-Braille, and text highlighting tools make it valuable for blind, low-vision, dyslexic, and others with reading differences.
Use it to import or take a photo of anything containing text. Take a photo and the app reads text out loud or displays it on a connected refreshable Braille display.
Developer: Sensotec nv

Light Detector
If you are blind, Light Detector helps you to be more independent in many daily activities. At home, point your iPhone towards the ceiling to understand where the light fixtures are and whether they are switched on. In a room, move the device along the wall to check if there is a window and where it is. You can find out whether the shades are drawn by moving the device up and down.
Developer: Retina Italia Onlus

NFB Connect
The improved and redesigned NFB Connect app is here! Get up to date on the latest Federation news. Read posts from our blog, the Voice of the Nation's Blind. Listen to the Nation's Blind podcast, the Presidential Release (in English or Spanish), the Braille Monitor, and Future Reflections.
Developer: National Federation of the Blind

VO Calendar
VO Calendar is a weekly calendar specifically designed to be used (only!) with VoiceOver. The result of this VoiceOver-only design is not only a smoother navigation through the app. It also makes it possible for the VoiceOver speech to give smart summaries depending on the context. This prevents you from having to go through each event individually.
Developer: Devista B.V.

Voice Dream Reader
The visually impaired will benefit from the ability to hear documents read in their favorite voices; and everyone who wants to hear or read their documents in their own way will benefit from the configurability of the visual and voice capabilities. Voice Dream Reader supports reading PDF, DRM-free EPUB and DAISY eBooks and more.
Developer: Voice Dream LLC
SPEECH

CoughDrop AAC
Simple, modern AAC communication and support tool that empowers individuals and the teams around them. It is a full-featured communication app built for individuals with autism, cerebral palsy, Down syndrome, Angelman syndrome, Rett syndrome, or other complex communication needs.
Developer: CoughDrop, Inc.

Lamp Words for Life
LAMP Words For Life™ is a full English vocabulary augmentative and alternative communication (AAC) language app that combines the power of the PRC Unity® language system with Language Acquisition through Motor Planning (LAMP™) principles and strategies
Developer: Prentke Romich Company

Predictable – AAC app
Exciting text-to-speech application offering customizable AAC functions with the latest social media integration, Predictable sets a new benchmark for the Android OS. The word prediction engine meets the needs of a wide range of AAC users, including those with MND / ALS, Cerebral Palsy and people with communication difficulties after a stroke or head injury.
Developer: Therapy Box Limited

Proloquo2Go
Proloquo2Go is a symbol-based communication app that gives a voice to those who cannot speak. Over 200,000 people already use this AAC app as a powerful tool for expressing themselves and increasing their communication skills and language development.
Developer: AssistiveWare

Socky – Autism communication
First personal assistant to bring the words out for our unique children with Autism and ASD making it extremely easy for children to interact. Send one-tap messages using a huge vocabulary of symbols, Text to speech for the child - your message and every symbol is expressed vocally, send multiple-choice questions, send device-to-device messages like on Whatsapp or Messenger.
Developer: Ola Mundo

SymboTalk – AAC Talker
SymboTalk is a free app that talks for you by clicking on symbols (images or icons). The app has predefined communication boards from different areas of life, each board contains symbols (images). Clicking on a symbol reads it aloud and adds it to a sentence which can also be read. This way SymboTalk can be your voice and talk for you.
Developer: Elad Elram

TalkTablet – AAC
Award-winning TalkTablet is the only fully featured symbols-based AAC app that is avalaible for iOS, Android, Windows and Kindle devices...with the ability to share buttons and pages between platforms. This version is for Android devices only.
Developer: Gus Communication Devices Inc

TippyTalk EDU
TippyTalk is a new picture to text technology, allowing instant 2-way communication between a nonverbal person and anyone they choose. TippyTalk also focuses on name first communication moving away from the I WANT, I NEED statements used by other systems.
Developer: TippyTalk
COGNITION

CoughDrop AAC
Simple, modern AAC communication and support tool that empowers individuals and the teams around them. It is a full-featured communication app built for individuals with autism, cerebral palsy, Down syndrome, Angelman syndrome, Rett syndrome, or other complex communication needs.
Developer: CoughDrop, Inc.

Socky – Autism communication
First personal assistant to bring the words out for our unique children with Autism and ASD making it extremely easy for children to interact. Send one-tap messages using a huge vocabulary of symbols, Text to speech for the child - your message and every symbol is expressed vocally, send multiple-choice questions, send device-to-device messages like on Whatsapp or Messenger.
Developer: Ola Mundo

TippyTalk EDU
TippyTalk is a new picture to text technology, allowing instant 2-way communication between a nonverbal person and anyone they choose. TippyTalk also focuses on name first communication moving away from the I WANT, I NEED statements used by other systems.
Developer: TippyTalk
MOBILITY

The Google app keeps you in the know about the things you care about. Set up and use voice commands in Google Assistant. Find quick answers, explore your interests, and get a feed of stories and updates on topics that matter to you. The more you use the Google app, the better it gets.
Developer: Google LLC

HouseMate Home Control
Allows you to control everything from one device: Turn on your room lights and close the curtains. Change channels on your TV and turn up the heating. Answer a phone call and send some texts. Browse the Internet, play some music or watch YouTube. HouseMate hardware in combination with an iOS device enables you to do this and much more.
Developer: Brian Dillon

Tecla
Tecla is the companion app to the tecla-e assistive device, giving individuals with physical disabilities the ability to communicate, control and connect with the world from a mobile device.
Developer: Komodo OpenLab Inc.
Source: https://www.razmobility.com/ios-accessibility-applications/
Note: *RAZ Mobility or Special Needs Computers is not the developer of these applications and does not assume any liability or responsibility related to their use.