It's easy to get cynical about voting, particularly if you live in a constituency where there already appears to be a clear winner.
But it's imperative to vote, particularly when it looks as if we may face another hung parliament.
Channel 4's new app, developed to encourage under 25s to vote, highlights the power of the "non-voters". David Cameron had a majority of 22,740 in his constituency, yet nearly 21,000 of its adult population did not vote. East Ham has a huge Labour majority of almost 28,000, but an even bigger 40,000 failed to vote. Manchester Central had the highest number of non-voters in 2010 totalling more than 50,000.
See? Your voice can count - as long as you vote.