I would start by describing WhatsApp core features and strengths. WhatsApp is a free communications mobile app which enables users to have a very fast, easy and reliable way to establish a conversation with another person or group of people (being the group feature widely used by its users base).
I thought whether we had the information or not about the user age in order to provide different features based on it, but I am assumming here that we don't have access to that private information so therefore we don't know the age.
In order to make it "more user friendly" for the elderly, we need to focus on what "user friendly" means for the elderly, and "who" the elderly is. I will ask if it's ok to assume we're targetting people of age > 70 years old. And I will say that make it more user friendly means allowing them to perform the task they want to perform creating the less friction possible.
I would go through the user journey of using whatsApp and its features for the elderly:
-Download app from the store
-Accountkit validation to verify number.
I will be assuming here that the elderly receive some help on how to do this and this is not a pain point for them as it's a one time thing. I'll also assume that whoever sets it up has defaulted font size to a size they can read and write appropriately.
Once they have the app up and running, here's what they might want to do:
I think they would also receive help the frirst time but once they face the task by themselves, they are likely to encounter challenges.
1) Start a text conversation . In order for a conversation to happen, there is a need to find the contact they want to talk to.
2) Send / listen to a voice message.
3) Make and answer a call.
4) Create a group (I will leave out the option of creating a group as it is a more advanced feature and I am assuming they are being invited instead of creating their own groups).
I would ask if it's ok to assume that 1 through 3 are the most common tasks an elderly would like to perform, assuming they want to keep in touch with certain relatives like grandchildren who might live far away, and be able to be reached by their children on a regular basis. If yes, I would try to come up with ideas of why these tasks can present a challenge to the elderly.
Here some ideas:
1) In order to start a conversation the user has to tap on the "message" icon. This can be pretty straightforward as the icon represents the "send message" action for the young and adults, but probably not for an elderly person .I would run user interviews to validate if this is or not a problem. In this exercise I'll assume it is.
2) Once in a conversation not only messages but voice can be exchanged. I will assume that the listening is a intuitive task , but not so the speaking to someone. There is a microphone icon next to the text input but you need to actively press it (or do another gesture) to start the recording.
3)In order to start a call, similar to 1, one needs to find a contact. And then you need to find the "Call" which might not be not easily seen as it's placed in the right header next to the settings. Also, for picking up one has to slide on the call icon ? I am not sure if it works like this and I will assume it does work in this case this might be an issue for the elderly as they don't know how to accept the call.
So now trying to look at solutions for their pain points (which I would actually extract from a usability test where they would interact with the product):
For 1) and 3) I am assuming that most elderly will have few contacts (something can be easily extracted from data). Therefore, I would evaluate directly presenting the unitiated conversations with up to the 5 most frequent contacts already loaded on the conversation screen as they open the app. The cost for this is low, and impact is high. In many cases, this will solve the finding a contact challenge. This experience is similar to the one offered by their OS when trying to send a message or make a call. Also, I think this feature will be nice for the young and adults users as well.
For 2) I would consider making the process of recording more standard. Instead of having to press it, one click would be enough to start the recording, and another clic to pause it.
For 3) I would prototype different places to put the call action and see which one is the most successful one. In the group, I would do it with the elderly but I would also then run a test with other groups to confirm this has no impact on their experience (or even, enhances it). For the answering issue, just tapping on the accept would get the call through.
I think this is challenging as the main population targetted is people who don't find WhatsApp not to be user-friendly. There is a risk too about redesigning it for an elderly and hurting the wider base of user experiences. I think a "learn how" section could be a good idea too, so that it's available for people that need it.