Back at the turn of the millennium, the management experts Jeffrey Pfeffer and Robert Sutton coined a phrase to describe the biggest hazard of business life: the “knowing-doing gap”. People mostly know what changes they need to make, they argued; the problem is making them.

Of course, the gap isn’t confined to business: it’s a major barrier to personal change, too. And the phrase is especially resonant in these dark political times, when every third conversation seems to involve people pledging to do their part to resist the rise of authoritarianism, fearmongering and bigotry. A noble sentiment – but you have to actually go to the protest march, make the donation, volunteer for the community organisation: you need to cross the knowing-doing gap. How? I don’t have a panacea. But I’ve been hugely helped by an ingenious Dutch app, available for iPhone and Android, with the arguably unfortunate name of Braintoss.

I’m flirting with absurdity, I realise, in suggesting a smartphone app as a partial solution to grave political challenges. But bear with me. When you open Braintoss, it gives you three options for making a note – writing, recording audio, or taking a photo – then sends the note to your inbox. That’s it. It does nothing, in short, that you can’t do with other apps, or by emailing notes to yourself. But crucially, it does only that, with a minimum of keystrokes – and unlike when I email things to myself, there’s no risk of being dragged into reading or replying to all my other messages. The process takes seconds. I’m struck by a thought (a book I want to read, a person I should contact, an event I ought to attend), I make a note, and it’s waiting in my inbox.

This translates into action, because email, in my life at least, is the place where stuff gets done. Sure, I can stick Post-it reminders on the wall above my desk, but I know they’ll just become decoration. I could take memos in another memo app – but then I’d have to check my memos, as well as my email, and realistically that’s not going to happen. Braintoss exploits the same principle as leaving something on the doormat if you want to take it to the office: identify the bottleneck in your life where things already do receive your attention, then put what really matters there.

In the context of great battles over politics, or the fate of societies, this talk of inboxes and apps may seem soul-crushingly mundane. But that’s the point: however world-changing your aims, it’s only through mundane actions that you’ll ever get from knowing to doing. I recall a banner outside a Quaker meeting house in Washington DC, some time around 2004, that read, “What have you done today to remove the causes of war?” Some exemplary citizen with a marker pen had crossed out “the causes of war” and written “Bush”. Today it would be “Trump”. But the message, in all three versions, is the same: you have to find a way to actually do the thing – to build some kind of rope bridge, no matter how makeshift, across the knowing-doing gap.

oliver.burkeman@theguardian.com