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User manual


Lazzus, currently available for Android and iOS mobile devices, is an application aimed to help the blind and visually impaired. Lazzus allows its users to gain better spatial orientation and get a rich, improved perception of their surroundings. For these purposes, Lazzus combines GPS technology with the use of sensors in the mobile device, so as to generate a “virtual field of vision”. This allows the user to handle their device as if it had turned into a flashlight, whose light beam would then be this new, virtual field of vision. This way, just by orienting their device, the user will be able to perceive what is located wherever they project this "beam of visual field" generated by Lazzus, as all the information will be transmitted to the user by sounds and artificial voice. Lazzus has some other functionalities such as the obtention of its user's current location and a list of nearby attractions (sorted by their distance to the user). It also offers the possibility of filtering these results by categories and adding the user's own places.

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Quick guide




The requirements for each platform are the following:

  • Android 4.0 or higher version
  • Screen size: larger than 3-inch and smaller than 8-inch
  • GPS (Glonass is recommended for higher precision)
  • Digital compass or magnetometer
  • Internet connection (an average monthly consumption of 5.6MB is estimated if used every day)

iOS (iPhone)

The requirements for each platform are the following:

  • iOS 8 or higher version.
  • iPhone 4s or higher version.
  • Internet connection.


The application has been developed in collaboration with experts on accessibility, and it has been validated by organizations such as the CIDAT. During its development, different tests were carried out by a group of 30 users with visual impairments, in different geographical areas, and for extended periods of time, with satisfactory results.

Moreover, for each of the platforms, we have followed the development recommendations for accessibility, checking its functionality for Talkback and Voiceover, the accessibility mechanisms of the Android and IOS systems, whose details are explained as follows:


Talkback is the Android accessibility functionality. It can be activated from the accessibility submenu, when clicking on the device settings option. You may find detailed information on its functioning on the following links:

Even if Talkback is not activated on the device, Lazzus will play all its voice messages. This can be useful for users employing a magnifier or magnified text, who may not activate Talkback.

Using braille devices is also possible, thanks to the BrailleBack Google application, which works together with TalkBack. Further information on its downloading and a list of supported braille devices can be found clicking the following link:

Despite the fact that all Android terminals offer this accessibility mechanism, it is recommended to use devices with unadulterated Android versions (Google Nexus), as some manufacturers may add interface layers, which could considerably reduce accessibility. Avoiding installing launchers is also recommended.


VoiceOver is the accessibility system for iOS (iPhone). Its activation is extremely simple: just press the home button 3 times. We can also use the classic activation method, via the settings menu. For further information on its functioning and features, click the following links:

Even if VoiceOver is not activated, Lazzus will play all its voice messages. This can be useful for users employing a magnifier or magnified text, who may not activate VoiceOver.

Braille devices can also be used with no need of installing any external application. The only requirement is to activate VoiceOver and connect to your terminal any of the braille devices listed under the following link:

First use

When Lazzus is started, its first use will significantly differ from the future ones. The starting-up process is explained as follows.

Annual license

Lazzus is a payment application (with a free trial version of seven days). The annual license cost is 22.99 pounds, and the user gets unlimited functionality for this period (365 days). You can also purchase a monthly license that costs 3 pounds 99 pounds for a period of 30 days. Therefore, once the application is installed for the first time, it will be available for a free trial period, and when it expires, a payment will be required. This payment can be made directly from the application, transparently to the user, who only needs to fill in the purchase form with their Google Play or App Store credentials.

Once the purchase has been completed, the user, optionally, can enter an email address, to be used to recover their account in case of uninstalling, or if the user changes his terminal (or platform). Therefore, completing this information is recommended.

Finally, whether the registration is completed or not, the main menu will be displayed. This main menu will be displayed by default whenever the application is started, until the license expires.

Account Recovery

In case users need to reinstall the application or if they change terminals, Lazzus incorporates an account recovery mechanism, so as to restore the previously acquired license.

To start this process, simply press the "Restore Account" button, which appears just below the "Annual License" button. Then you will be prompted to enter an e-mail address: you must enter the one you used during the registration process. A 6-digit code will be sent to that email address. Immediately afterwards, you will be required to enter this code, so as to finally conclude the process and restore your license in the terminal. The main menu will then be displayed. It will be displayed by default whenever the application is started.

Exploring mode

The "Exploring" submenu shows all the core functionalities offered by Lazzus, as explained below.

Visual Field

When accessing the "exploring" submenu, Lazzus will automatically locate the user’s position and proceed to download the location of nearby places. Lazzus will also create an artificial field of vision, so the system will be able to indicate intersections, businesses, obstacles or other points of interest located within this field of vision. The user may handle this virtual field of vision as a flashlight beam, that is to say: the user can orientate their mobile phone, as if it were a flashlight, towards wherever they want to create their virtual field of vision. This mode is the so-called Beam mode.

Lazzus has another exploring mode which is Lazzus 360. This has been conceived so that you may keep your mobile phone in your pocket without having to point it towards the place you wish to explore. With this mode, Lazzus recognizes every place around you, in any direction, or in other words 360 degrees.

It is important to point out that Lazzus does not use the terminal camera, so it does not matter if this one is covered. What is really important is to avoid placing metallic or magnetizable materials near the device, because they can interfere with its sensors, increasing their potential errors.

It is also recommended to handle the device horizontally (although not strictly necessary) and avoid placing it in closed compartments (like a suitcase), in order to improve the accuracy of the GPS signal.

The points of interest will be indicated by sounds when they are located in the vicinity of the user's virtual field of vision, on its right or left. When the points of interest are located exactly in the center of this virtual field of vision (which means they are just where the mobile phone is pointing), they will be indicated by synthesized voice and a high-pitched sound.

The indications about points that have already been visited will be repeated every few seconds, in order not to overwhelm the user and allow him to pay attention to some other places.

Many of these parameters are configurable and may be adjusted from the settings menu.

Besides, there is a transport mode, which is activated automatically when Lazzus detects the user's speed is too high. Thus, Lazzus will indicate the street and number where the user is, updating this information every few meters.

Additional features

My position

As the name suggests, this option indicates where the user is at a certain time. A message is displayed with the street number, zip code and city.

Add favorite places

In addition to the points of interest provided by the app, each user can add their own points, which will be located only on their own maps. To do so, you need to be in an area with good GPS accuracy, then, enter the name of the place and click on "accept".

The location of these personalized points of interest will be exactly the user's location when they add these places to their maps. So this functionality is designed to incorporate some own favorite places, as the user's home, a friend's, their workplace, etc.

Apply filters

Lazzus will display all points of interest by default, regardless of their category. However, many users may prefer to receive information on a specific category, so Lazzus offers the possibility of selecting the groups of categories the user wants to be displayed.

The points of interest Lazzus consider are classified into categories and groups of categories (which are the ones that can actually be filtered). Here is a list showing the current Lazzus classification:

  • Transport
    • Airport
    • Bus stop
    • Cab
    • Subway/Underground
    • Train
    • Tram/Streetcar
    • Car park/parking lot
    • Gas/Petrol station
    • Rental
  • Leisure
    • Bar
    • Pub
    • Restaurant
    • Nightclub/Discotheque
    • Cinema
    • Theatre
    • Museum
    • Ice cream shop
    • Cafeteria
    • Casino
  • Sports
    • Gym
    • Stadium
    • Swimming pool
  • Education
    • Library
    • University/College
    • Primary School
    • High School/Secondary School
    • Kindergarten
  • Shops
    • Vending machine
    • Shopping center
    • Kiosk
    • Beauty
    • Electronics
    • Business
    • Market
  • Finances
    • Bank
    • ATM
  • Health
    • Hospital
    • Pharmacy
    • Clinic
    • Dentist
    • Nursing
    • Vet
    • Optics
  • Lodging
    • Hotel
    • Hostel/inn
    • Youth hostel
  • Movility
    • Crosswalk/Zebra crossing
    • Stairs
    • Traffic light
    • Obstacles
    • Intersections/Crossings
  • Public services
    • Police Station
    • Firefighters
    • Information
    • Town Hall
    • Courts
    • Embassy
    • Fountain
    • Park
    • Bank
    • Toilets
    • Post Office
    • Mailbox
    • Bin
    • Public phone
  • Favourite spots:
    • Custom (added by user)

List of nearby locations

Quite often, users want to know the location of many places in their surrounding area, even if these places are outside their field of vision. This usually happens when looking for a specific place.

This option allows getting a list of nearby places within a radius of 100 meters, sorted by distance. Their orientation is provided clockwise from the device location.

Besides the user will be able to access the details of the place on a new screen, where it will be able as well to initiate a route navigation using external tools in the phone (such as Google Places). Also, if the place has been included by the user, it can be deleted from this screen if necessary.

List of favorite places

At any moment you will be able to check your list of favorite places, access all its details and even start a route to go to its locations. Any place you add will be marked as favorite by default, no matter if it has been added from the application or from the administration web page. You will also be able to bookmark any other place by accessing the detail screen.

Activate Lazzus 360 or Activate Vision field mode

With this button you will be able to change the exploring mode at any moment without having to stop the current exploration.

Mute exploring

With this button exploring indications will be muted whenever you wish.


Lazzus aims to adapt to every user’s needs, so different setting options are available, as detailed below.

Basic settings


When activated, this option informs of the distance to the point of interest (located within the user’s field of vision), as well as its name. It is not activated by default, as the field of view has a relatively small depth. Enabling this option is especially important when the user adjusts the viewing distance to its maximum level.


This allows you to maintain active orientation indications, which will be given in the Lazzus 360 exploring mode or in the list of nearby places. Orientation modes are: clockwise orientation (twelve, one, six, etc.), and directions (front, front right, right, back, back left, etc.).


When activated, this option allows the user to identify the category including the point of interest located in their field of vision, besides its name. It is enabled by default.


When enabled, acoustic sounds are reproduced, indicating:

  • Point of interest entering the field of vision from the left
  • Point of interest entering the field of vision from the right
  • Point of interest located at the center of the field of vision for the first time (in the same session)
  • Point of interest located in the center of the field of vision the following times (in the same session)

The functioning of these sounds is explained through an example reproduced on the app tutorial. This tutorial will be played by default the first time the user accesses the exploring mode.

Side sounds

When this option is turned off, the app won't reproduce sounds indicating that a point is entering the field of vision from its left or right. This option only makes sense if the previous option is activated. It is enabled by default.

Street changes

With this option Lazzus detects when the user turns onto a different street, and it indicates this information automatically.


It restores the app tutorial (the one played when the exploration mode is accessed for the first time).

Advanced settings

Exploring mode

This allows you to set which exploring mode you prefer:

  • Visual field.
  • Lazzus 360.

Orientation mode

This allows you to set which orientation mode you prefer:

  • Clockwise.
  • Directions.

Vision field: range or amplitude

This option adjusts the amplitude of the angle forming the triangular field of vision. Values for this angle can be:

  • Highest: 70 degrees (by default).
  • Medium: 60 degrees.
  • Low: 50 degrees.

Visual field: length or distance

This option adjusts the distance (length) of the triangular field of vision. Values can be:

  • Highest: 20 meters.
  • Medium: 15 meters (by default).
  • Low: 10 meters

Restore defaults

This option resets the application default settings, as if a new installation were made.

Extra settings

Map activation

This superimposes a map with satellite view over the exploration mode. This option makes sense only in the case of people without visual impairments, who may want to visually check the exploration mode performance, and/or detect possible malfunctions (as a result of calibration errors from the sensors, poor GPS coverage, etc.).


The user may check their license status by clicking the "About Lazzus" option, on the main menu. This screen will display how many days are left till the user's license expires, together with the privacy policy of the app. It can be checked at any time. Here you may also add a recovery email, if you have not done so previously on the register screen.

Latest news

In the main menu there is also the option of checking for the latest updates. Here you can find the features that have been added to the application recently. These improvements appear in chronological order.

Technical support

For any technical questions or problems with the application, please contact us at support@lazzus.com, from the menu option called “Support”.

Useful links

MP3 version of users's manualMP3 version of user's manual