The two saddest words in the English language, it’s often been said, are “if only.”

Our lives are like a breath; our days like a fleeting shadow (Psalms 144:4). Our loved ones pass away and we can no longer share their presence. “If only…” is the universal cry of the bereaved desperately seeking continued connection and conversation with those who made their lives meaningful.

If only I could hear my mother’s voice once again reassuring me of her love, granting me more of her wisdom. If only my father could be here with me to give me strength and courage. If only I would’ve asked them the questions I never bothered to ask. If only I would’ve gotten to truly know them as my closest friends. Death, it would seem, has closed the door to any further interaction. Perhaps the greatest tragedy of death is its final verdict of silence from beyond the grave, its cruel response to “if only” with the harsh judgment that now nothing more is possible, it is simply too late.

Thanks to Gaby Eirew that seeming inevitability may have changed.

Gaby is the child of a Holocaust survivor. Her mother, Denise, was smuggled out of the Drancy camp in France in 1942 as a four-year-old by the French resistance, while her parents, unbeknownst to her, were murdered in Auschwitz. Denise was also given a fake postcard pretending to be from her parents, saying that if she cried for them, they would not come back – a way of protecting her, because it was feared that if she displayed any emotion about her parents it would draw attention to her true Jewish identity, and put her life at risk. Gaby’s mother never really knew her own parents, nor could she ever truly grieve for them.

Gaby Eirew with her mother Denise.

That awareness surely played a role in Gaby’s personal reaction to death of her father and mother-in-law in the space of a month, followed very shortly by the sudden passing of her best friend. She found herself overwhelmed by her own grief while at the same time trying to imagine the impact her friend’s death had on her three young children.

"I imagined my kids like hers, growing up with everything that they knew directly from their mum stopping there and then. I wanted to write to them all and reassure them and tell them the most useful things, but I could not sum her up. Some things I realized the children would hear from their father and grandparents, but some things would surely have to come straight from her," Gaby told BBC. The tragedy that befell Gaby’s own mother, never really getting to know the woman who bore her and gave her life, was now repeated albeit by other circumstances with the passing of her best friend.

Gaby became obsessed with death, with its finality and with its closure of possibility for further sharing. She went around, as she put it “like a lunatic”, asking hundreds of people, “what have you prepared for your death? What messages have you left for your loved ones?”

The app empowers you to continue your conversations with loved ones by way of messages prepared before taking leave from Earth.

And so was born the idea for a remarkable app that would help children both to mourn for their parents as well as in a sense to keep them alive. A free app that would help them to continue their relationship. It has been used by tens of thousands of people in more than 30 countries to leave a legacy of video messages for their families.

With technology, we can achieve a small measure of immortality – our image, our voices, our wisdom, our advice, our memories – on video recordings. If, when we leave on lengthy trips or seek to maintain contact with family living at a distance we make use of Skype, why not – Gaby reasoned – continue our conversations with loved ones by way of messages prepared before taking leave from Earth.

So Gaby surveyed thousands of mourners to find out what they most missed aside from the physical presence of the deceased. In that way the prerecorded messages could be relevant in the most personal of ways. And the findings were fascinating.

When she asked people what they most wished they could have asked their parents, "The single most important thing that people said they wanted to hear was that their parent was proud of them, that they loved them and to hear them say that with their name," Gaby says. "So often people were told that their mum or dad loved them so much, but they needed and wanted to hear it". demonstrating the importance, as parents, to take advantage of the opportunities to say those words to our children during our lifetimes. We just don’t say them often enough.

Sometimes mourners wanted to hear a very specific set of words. "They wished they could ask their parent, 'I remember you whispering something to me every night, what was it? I want to hear it again.' It could have been a prayer, or nursery rhyme or other words that became part of a nightly ritual and helped them know they were loved before they fell to sleep”. This reminds us of the importance of the seemingly unimportant – the rituals of everyday communication which convey our love and our values, such as putting our children to sleep by reciting with them words of the Shema.

Another discovery was that bereaved children often carry a huge amount of guilt. "For a parent to say in a message 'I'm sick, I'm dying, it's not your fault, I don't want to die, I'm happy you get to live on and you get to have a full life,' that's really important." And conversely, that will remind us that while are alive we must be careful not to give them lifelong guilt by implying that their disappointments are the cause of our failures.

Gaby was also surprised to hear many of the more mundane – and quite specific – questions that children had for their parents. What floor cleaner did you use? That smell reminds me of my childhood. What perfume did you wear? I want to wear it too. What is the recipe for that soup you used to make? Satisfying children's curiosity about these kinds of details can really help with grieving, she says. And perhaps the importance of these questions to mourners can make us far more sensitive to the importance of creating memories during our children’s lifetimes when we are still with them – memories like the smell of the kitchen preparing for Shabbat and the odors of the holidays and their special foods.

Essentially, Gaby summarized, they were looking for advice and guiding principles that would help them make important decisions as their lives unfolded without their parents. What a remarkable realization it should be for us that the most important thing we can leave our descendants is a legacy of values rather than a lucrative financial inheritance.

Gaby's app, called RecordMeNow, is essentially a series of prompts that helps people to create a video library for their children, broken down into subject areas, based on Gaby's findings. A key aim was to get parents to record that simple message in video form for posterity

Gaby’s mission, to have people record meaningful messages to their loved ones before their passing, has a biblical precedent. That is what Jacob did as he called his children to his deathbed for a final blessing. Jacob knew that his words of guidance would have far greater impact with the realization by his sons of his imminent death. Death lends unparalleled significance to the words of someone we dearly love.

The RecordMeNow app is like a digital update to this idea. For the time being it is one of the best ways I know of achieving a lifespan even longer than 120.