In 2010 the BBC had a page listing all the broadcasts with links to individual pages, which is not quite as nice to use but does the job.
In 2015 they shuffled the broadcasts in with all the other Election 2015 reports.
In 2017... it appears the only way is to search for "Party Election Broadcasts General Election" in iPlayer and hope something sensible appears. Importantly, I must not add "2017" unless I only want to see the NI parties in the results. And when I do find the video to watch, I have to click four different links to play it (first link goes to a programme page, then "Watch now" goes to the episode page, then the play icon on that asks if I have a BBC account or a TV Licence, and finally I can actually watch the thing).
I can't help but think that so much of the modern internet is one step forwards, two steps back. Especially the current trend to replacing any sort of index or listing with a search box that doesn't understand boolean operators or quotes and returns results in an apparently random order.
Anyway, I've finally found them and so it's time to work out which party to vote for (again). It's surprisingly tricky this time round - all of them have terminally stupid proposals in their manifestos, most of them have surprisingly sensible ideas as well, and none of them come out particularly on top. And that's before you start considering tactical voting (since the most important thing is obviously to stop the Evil Tories, nevermind who wins as a result) or the fact that your preferred party might not even be standing as part of a pact (the Greens are staying out of some constituencies to help Labour or the Lib Dems, while UKIP are doing the same to help the Conservatives). It almost makes one want to give up on the whole thing and vote for the Monster Raving Loony Party...
So. I shall begin with Labour... who say it's all terrible these days but if you vote Labour they can fix everything and make a society that works for everyone.
On the other hand the Conservatives point out that it's all about Brexit and whoever wins has to make Brexit work. Somehow. Oh, and if the Tories win they'll also make a society that works for everyone.
The Liberal Democrats want to make it clear that there is another choice, and while no-one knows what will happen next the Lib Dems can give you lots of choices.
UKIP are trying to work out what everyone's thinking so they can say what they think everyone's thinking. And you can't trust Labour or the Tories because they're clearly in cahoots with each other.
The Greens have their latest board game on show - The Race To Number 10! Don't forget, in this game, nobody wins!
Plaid Cymru are worried that no-one even knows Wales exists, so they plan to invade Westminster to stop marauding Labour and Tory governments accidentally invading Wales.
Finally, the SNP are all about how awesome Scotland is, and how to keep Scotland awesome they must also invade Westminster to stop marauding Tory governments deliberately invading Scotland.
It's a rather depressing set of videos. The theme is definitely "everything's terrible, but if you vote for us then we might make things slightly less terrible" (except for the SNP who claim it's merely England where everything's terrible).