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B2C Anti-aggression social app & IoT wearable


I spent 1y working on an efficient solution to stop street aggressions. I started this journey by participating in and winning the James Dyson Award, before launching my SaaS start-up and focusing on finding a great community-based app using extensive testing, interviews & Agile-based methodologies to find a viable solution to this worldwide problem. 

What is it?

b-eve is a suite of two products combining the power of both hardware IoT device & companion app social features:

  • ​IoT Device: This wearable bracelet solves the key problems of triggering anti-aggressions solutions when aggression occurs. By saying a keyword or shaking the wrist, it records the aggressor's voice, calls for help, sends GPS coordinates and triggers a heavy 100dB alarm to scare the aggressor.

  • Social Companion app: 90% of street aggressions happen when women are alone. The app solves this problem so that aggressions don't happen in the 1st place, by allowing users to meet up and walk back home together.

How did I validated it?

To build these 2 products, I conducted intensive user research of victims, security experts and policemen. I visited 2 emergency call centres to gather insights on this highly complex topic and understand why all the current solutions fail to solve this problem.


User testings


Website visitors


Research surveys


Website visitors


Tested app


Expected Gross M.


Tested IoT concept


Award Winner 2019


Video in 48h 

b-eve mobile app & IoT Bracelet



3 months



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1 month




In this Phase, I defined the vision and market fit that ruled the product throughout the entire process. To do so I analysed the market and ran intensive user interviews to gather victims and police insights.

1. What are we solving for which market?

Image by Morica Pham

"Defend and empower women against the worldwide issue of public aggressions" 


When starting the project, I knew several friends who had been aggressed in public late at night despite owning anti-aggression solutions such as paper gas. I suspected there was a potential gap in the market worth exploring to try to solve this very complex problem. This led me on a 1 year journey.​

Defining a product target market 

As showcased by the below numbers, street aggressions & public harassment are worldwide issues that affects massive markets, showcasing a real business potential if a good product fit can be found.

  1. India

    • ​1st most dangerous country in the world for sexual violence

    • 80% of women have faced harassment in public spaces

  2. Brasil

    • In 2022, 7.4M women suffered physical violence

    • In 2020, 1 in 4 women suffered some type of violence

  3. USA (source Gallup survey)

    • In 2014, 45% of women did not feel safe walking alone at night​

  4. UK

    • In 2016, 75% of women living in London UK were victims of harassment or violence in public​​

I decided to focus on the French market

 It was easier for me to gather data from it (interviews, survey..). Therefore I looked for France focused figures (source INED, 2015):

  • 58% of women between 20/24yo have been victims of at least 1 violent act in public spaces​

  • 1M women are victims of sexual harassment and abuse per year in public spaces

  • Only 13% of sexual harassment and abuse victims in public spaces engage in legal procedure

  • There are 8M women between 15 and 35yo in France, which is the main street violence targetted age range

Defining the product focus

The word of 'aggressions' refers to multiple types of aggressions:

  1. Domestics violence: These are the most common aggressions-type. They are very hard to find answers to because of their highly private and repetitive nature.

  2. Public aggressions: Are more sudden and unpredictable, and targetted to mostly 16/30 yo women in most cases. Defence against them can be quite straightforward compared to the other types of aggression.

  3. Workplace violence: Lone women workers interacting with men are victims of multiple and repetitive aggressions (home nurses...) 

I decided to focus my product on the Public aggression spectrum. It was the one I was the most familiar with, and the one with potentially the most straightforward solutions. However there are multiple overlaps within 3 aggressions-types, and finding solutions for one does solve several problems for the other.

2. What is the competition landscape ?

The safety solutions market is a growing and varied one, with multiple overlapping indirect and adjacent competitors using similar sets of features for very different usage (elderly fall detection or factory workers safety bracelet..).

Find below a list of the most important groups of competition within this self-defence sector.

Intensive surveys & interviews helped us gather feedback on each one of these competitors (cf '4.Gather user needs & feedback' below)

Screenshot 2023-11-06 at 23.22.16.png

'Street safety' mobile apps

Direct Competition

  • Each country have their own apps, either from private businesses, owned by public organization or non-profit privates ones

  • They usually allow to easily share your location on your trip back home, tag a violent event you witnessed, and call for help in case of emergency

  • They are mostly free


Paper spray & 'hard' defense

Direct Competition

  • These products are made to directly 'fight back' against the aggressor

  • These are illegal in some countries and have many shortcomings, such as getting used against the victims

  • They are highly successful & and affordable products


Wearable alert trigger

Direct competition

  • These wearables offer quick access to an 'SOS call' or emergency SMS

  • They are usually dummy button that triggers mobile app features on the user's phone

  • The online price varies from 10£ cheap 'running bracelet' to fancy 100£ jewellery-looking products

Screenshot 2023-11-06 at 23.24.35.png

Workers accident alert device

Adjacent competition

  • These products are highly reliable technical products made available to professionals working in tough dangerous environments and factories

  •  These products are usually not available to the main public 

Screenshot 2023-11-11 at 18.55.58.png

Loud alarm & Flash

Direct Competition

  •  110dB alarms are made to scare the aggressors. They are cheap 5/15£ solutions available online

  • Same for the intense bright flashlights made to immobilize them for a short period of time

Screenshot 2023-11-06 at 23.29.55.png

Smartphone OS features

Direct competition

  • Apple, Samsung & Google have multiple safety-related features within their Operating system

  • It proves the large market interest for these types of products & features, but also shows the weakness of any startup in these area. 

Screenshot 2023-11-06 at 23.23.45.png

Elderly alert devices

Adjacent competition

  • These products are bulky technical bracelets, made to be highly reliable

  • They can be either dummy SOS buttons or contain smart fall-detection systems

  • Their price varies from 30£ to 100£ pounds online

3. Who is our product for?

  • '1 in 5 women' Vs '1 in 71 men' are victims of violence at least once in their life > The gender target will therefore be focused on women

  • The 1st women age group suffering the most aggression is the 16/19yo range 
    It represents a pool of 2M women in France

  • The 2nd age group suffering the most aggression is the 20/30yo age range
    It represents a pool of 4M people in France

Find below the Persona created following the above data.

The combination of Persona 1 & Persona 2 provides a total market size of 6M women in France.

This top-down market approach will have to be filtered down based on average income and location (targeting mostly city users).

A bottom-up market analysis could be done to verify the market size assumptions with more accuracy.

Intensive surveys & interviews helped us gather feedback and daily-life needs for each of these Personas (cf '4.Gather user needs & feedback' below)

Working in Cafe

Persona 1
High need, medium income

Independant Women

  • 20 to 35yo active women living in city

  • Use to commute on their own, go out & party

  • They can go home late and on their own

  • Second main target group of public aggressions worldwide

  • They enjoy tech & digital products, and like to feel empowered by technology

  • They have 35K£/y and + income

  • They represent a population of 4 million in France

Young Parents

Indirect Persona 1
Indirect need, high income

Family Carer 

  • 35 to 50yo active Parents

  • They want to ensure their 15/20yo daughter would stay safe while commuting alone

  • They enjoy tech products and trust it to take care of their children

  • They have high income and are willing to invest in something to keep their children safe

  • They can buy as many products as they have children meeting the Persona 2 requirements: They have a max purchase power of 2 million units

Image by Jarritos Mexican Soda

Persona 2
High need, low income

Independent Student

  • 16 to 19yo active citizen/student women

  • Use to commute, go out in a city environment most of the time.

  • They can go home late and on their own.

  • The main target group of public aggression worldwide

  • They are mainly using free-based services and social media

  • They have low income & purchase power

  • They represent a population of 2 million in France


Indirect Persona 2
B2B market

Lone workers women in high-risk environments

  • 25 to 50yo active women working in risky environment professions

4. Gather user needs & feedback

I ran intensive user research for several months, trying to understand how street aggression occurs.

  • Expert Interviews & visit of Emergency Call Responder centre: In-person visit of 2 emergency call centres at night - interview of 7 call responders & trained response police squad team

  • Open-invite forum talks with student women: Qualitative feedback & debate about multiple competitor solutions and how/where aggressions occur (how the aggressor behaved etc..)

  • Research Surveys: Hundreds of quantitative feedback about competitor product performance, street fears & insecurity


Based on these multiple feedbacks, I divided a 'typical' aggression into a 6-phase process. See below a dumb-down version of it:

Image by Kelsey Chance

Phase 1: Preparing to go out

  • 95% of street aggressions occur when the victim is on its own. Therefore the 'pre-going out' is key in preventing the aggression from happening

  • This phase is a source of apprehension for a lot of women that know they will have to walk home on their own

Screenshot 2023-11-10 at 17.07.22.png

Phase 3: Harrassment

  • Usual behaviours from female victims are to ignore the aggressor, walk away, and sometimes try to call someone

  • Harassment evidence is hard to gather

Image by Mat Napo

Phase 5: After-assault

  • Victim can end up in shock lying down on the ground for several minutes, incapable of calling for help or sharing their location

  • Victim can try to run home or to a safe place

  • Several victims can be 'shy' of what happened, and not call for any help afterwards

Screenshot 2023-11-10 at 17.03.27.png

Phase 2: Walking alone

  • At this stage, most women want to let some people know that they might be in potential danger. They already use multiple techniques to do so, using dedicated apps or text messages

  • Walking alone at night is a stressful moment for most women

  • Women use tricks to limit the risks of aggression (Pretending to be on the phone, strong surrounding consciousness...)

Image by engin akyurt

Phase 4: Physical assault

  •  The victim usually freezes, making it impossible for her to counter-react

  • The aggressor usually takes hold of the victim, making it impossible for her to reach out to any device

  • Women find it very hard to reach and trigger any of the existing solutions (alarm key-chain, tear gas, quick sos call on the phone..)

  • Goods carried by the victim can be stolen or ripped apart at that stage, making use of the phone or any other protection mainly useless

  • Counter-defense products like tear gas is usually turned back against the victim by the aggressor

  • Police force can take between 5 to 20min to get on site if an emergency call have been made on time

  • Police can only access the location of the phone emitter up to a 10km radius based on the closest antenna used to make the call

  • Gathering evidence of the aggression is hard 


Phase 6: Long-term effect

  • Long-term trauma is a recurrent thing for victims

  • Finding groups and people to talk about can be hard

  • If the victim decides to declare the aggression to the police, providing evidence is very difficult

5. Finding the market fit

Once I had gathered the data on competitor solutions and user feedback, I built a Product Positioning map to find a market gap within the current proposition. Here's what I found

  • At the moment of the aggression itself, the accessibility of the solution to repeal the aggressor is key. No product on the market offers an efficient counter-attack product that would also be highly accessible while being strained 

  • No Product combines the above with a proper pre & post-aggression service - allowing for GPS tracking, SOS warning  and support to the court

  • No product targets the challenge that "95% of aggressions occur to lone women in the street". Allowing women to go home not alone will always be more efficient than any defence system.

Here's a dumb-down version of the feature matrix I built:

Phase deliverables

  • 'Competitor product breakdown': An exhaustive list of all the direct & indirect competitors, with feature breakdown & user feedback about them (find both online and using my own interview/survey data)

  • 'Market fit analyses': A clear analysis of where the product should sit on the market

  • 'Aggression-process breakdown': An analysis of the 6 phases of aggression and user needs throughout them

Phase challenges

  • It was challenging to apply the Lean methodology to such a complex & social topic

  • User interviews were hard to run because of the nature of the questions I had to asks about the assaults

  • Visiting an emergency call centre at night time and listening to these calls of profound distress were very hard



Using all the data, user feedback, business requirements, strategic vision, and competitor analyses gathered previously, I kicked-off a 2 sprints of feature ideations, from blue-sky workshop to an organized & ranked feature set to explore and trial later on.

1. Find features & solutions for each user need 

The first step was to use each user need detected in the 6 Phases of aggression and try to find solutions against them. The decision of going hardware, software or both combined was still open at that stage.

See below a dumb-down version of it:

3. Combine features into meaningful Groups

Once I had this library of features, the next step was to define how best to interface and provide them to the end user. I therefore separated 2 sets of features out of it

  • Cloud-based app service  for prevention

    • Takes full advantage of the software's internet capabilities to build social & community-based features that would work at preventing aggressions from occurring

  • IoT device & companion local app for defence​

    • Takes full advantage of the phone capabilities to call for help & record/share GPS location

    • Takes full advantage of the hardware to be the 1st hand-free activated device. It could be triggered under complete immobilization by the aggressor, or even if the phone is stolen

The detailed feature set of each product (digital & hardware) would be refined and tested later throughout the iterative trial & error AGILE process.

1. Mobile app: Safety features

  • Share the user's live GPS location for close ones to watch over the user going home

  • Quickly send an SOS message with GPS location to the Police force and/or contacts

3. Mobile app: Set-up the IoT device features

  • Set-up the IoT device

2. Mobile app: Social features

  • ​Compare ways home to find the safest

  • Find other people to commute and walk with

  • Get in touch with other victims of aggression

  • Find quick help in your surroundings when being aggressed

  • Find safe places

  • Advice & contact on what to do after an aggression

4. IoT device: Embedded features

  • Hand-free activation of the defence mechanisms

  • Loud 100dB alarm to scare the aggressor

  • Aggression audio recording

Phase deliverables

  • 'Feature set matrix': Detailed breakdown of all the features ideas, which data they require, and on which interface (mobile or IoT) they would be most relevant

  • 'Feature Groups definition & Prioritization'

  • 'Business plan' 

Phase challenges

  • Finding entirely new defence methods was very hard, if not impossible. The challenge was to provide them in a way that actually helps the end-user.



I now had to define how to develop & test both products: the social app & the IoT device.

1. Prioritization & Planning

Design & validate the IoT solution + mobile app defense solution - 2 months

  1. Validate the feature-set​

    1. Run Concept validation interviews​

  2. Validate the form factor & HMI

    1. Design & Build multiple hardware mockups​

    2. Run usability testing​

  3. Refine the final MVP product feature set, design & interaction

    1. Use 'Shadow button' methodology to validate the final purchase intent

  4. Size the product manufacturing cost

  5. Take a decision on the cost viability 

Design & validate the Social app solution - 2 months

The mobile app design consisted in cycle through the 3 steps below, until finding a successful concept

  1. Iterate solutions & build an MVP wireframes

  2. Validate the concept

    1. Run Fake landing page concept

    2. Run Concierge testing

Image by Marissa Grootes


This phase was key in building an actual solution for both the IoT device & the social app that came out of the ideation. It is through their validation that I discovered their flaws and had to make the choice between continuing with this entrepreneurial project or not.

1.1 IoT Product - 1st iteration & validation

Using the feature Groups established in the previous Ideation Phase, and after a 2-month design process, I built the below product proposal.

Click on the picture to get a full breakdown of how the product works & what it offers.