Author: Daniel Guillermo Alonso
Date: May 2022
For this analysis we have used version 1.0.1 (Updated on October 22, 2021) in a smartphone Android.
User interface
When you open the application you can see that it has a design that highlights clarity and minimalism, with a category where you can see the available signs and another called documentation where you can find information about the Dactyls system and deafblindness. Below, we delve into the options that are available within the two categories mentioned.
Signos: In this category you can consult and learn the different signs of the Dactyls system, and depending on the search you want to do, different options are offered:
- Searcher: This option allows us to do a manual search for the signs we want.
- Themes: Here we can find all the signs of the Dactyls system included in the application grouped by general themes.
- Categories: It is the same concept as grouping by subject, but in this case they are grouped by grammatical categories, expressions, groups of words and groups of signs.
- Dactylological: Here you can consult the dactylological alphabet in Spanish, which is the most used among deafblind people to communicate.
On the other hand, it should be mentioned that every time we enter a specific sign, the following interface is displayed:
This interface is very complete, playing a video with the execution of the selected sign that can be seen from a front view and a side view, and providing a written description that explains step by step how to perform said sign.
Pressing the icon 
we can play, pause or repeat the video and with
the same but playing the video in slow motion. If we press
the video will be played in full screen. Pressing the settings icon 
We will be able to select if we want to load the video with data and choose the video quality (High at 1080p, medium at 720p or low at 360p) for when we play it via Wifi and for when we do it through data.
Documentation: In this category we can obtain detailed information about the Dactyls system and deafblindness. The information is classified by different themes, which are: information about the Dactyls system (by clicking on the “Dactyls system”), information about deafblindness (by clicking on “Deafblindness”), documentation about how to teach signs (by clicking on “ Enseñanza del Dactyls") and data about the application and its version (Clicking "About").
Technical performance
Reliability
The application has not presented any failure or blockage during the analysis period, being able to navigate through it quickly and smoothly.
Consumption
During the analysis, no significant increase in battery consumption was observed. The data consumption will only be necessary to load the demonstrative videos of each sign.
Versatility and compatibility
Dactyls is a multiplatform application, and we can access it:
- Through your application smartphone o tablet with Android operating system version 4.1 or later.
- Via iPhone or iPod touch running iOS version 12.0 or later.
- Via iPad with a version of iPadOS 12.0 or later.
- Via Mac with macOS 11.0 or later and with the Apple M1 chip.
- Through its web version.
Security and privacy
According to what the application itself indicates in its "About" section: "Through this App ONCE does not collect or process personal data of users."
Accessibility
Regarding the interface, it presents a simple and easy-to-use design, with icons and texts of an acceptable size.
The app can be used with screen readers like TalkBack for Android and VoiceOver for iOS, increasing accessibility for people with low or no vision.
In this review we have tested the TalkBack screen reader for your version of Android and we have verified that all the options, buttons and texts are correctly labeled and will be pronounced when you pass your finger over them.
Conclusions
Dactyls is an application that, through a simple interface, manages to be very effective in its main objective: to make the Dactyls communication system known in a clear and complete way to facilitate interaction with deafblind people. To do this, it provides useful and extensive documentation, as well as detailed information on each sign accompanied by videos for better understanding.
It is, therefore, a very useful application if what you are looking for is to learn about deafblindness and the communication systems used by deafblind people, especially the Dactyls system.
Highlights
- Its simplicity, with very clean and clear menus that leave no room for error.
- The amount of information that is provided about the Dactyls system, providing demonstration videos and detailed explanations on how to make each sign.
- The informative mission that this application supposes, promoting making known to the greatest possible number of people a very useful form of communication with people with deafblindness.
Improvement points
- Perhaps in some sections, such as the indexes of the documentation topics, a slightly more attractive and attractive design is missing.
