I've updated my list of online British newspaper archives. This time, the new titles are:
Aberdeen Journal
AJR Information
Catholic Herald
Connacht Sentinel
Cork Examiner
Jewish Chronicle
Irish Press
Irish Times
Kilkenny People
Louth and North Lincolnshire Advertiser
Nenagh News
Northants Evening Telegraph
The Post/Sunday Post (Dundee)
Sligo Champion
Sowerby Bridge News
Many of these are Irish, mostly from from the Irish Newspaper Archives but a couple from the British Newspaper Archive. [edit: I actually forgot my self-imposed rule to only include Irish newspapers before 1922 -- oops!] Thanks to a list of newspaper archives at Wikipedia, I also found the Irish Times, a couple of London-based Jewish newspapers (one, AJR Research, free) and the free Sowerby Bridge News, which appears to be an individual effort. Another great free resource is the Catholic Herald -- for example, here's their response to Guernica, 'Open town bombing a regular practice of Reds'. In addition, 14 titles have increased year coverage, though sometimes this is only a year or two.
With respect to the US-based NewspaperArchive, there's some good news, some other good news, and some bad news. The good news is that they have overhauled their interface and it's now much easier to use. For example, they have adopted Trove-style filters so you can quickly narrow a search by time period or location or title. This means it's more useful for discovery purposes, whereas before it was more difficult than it had to be to find things that you didn't already know were there. The other good news is that they have mostly cleaned up the metadata for their British titles. Previously if you went looking for British titles from the 20th century you would get a lot from the 18th especially, but also the 17th and 19th centuries. Maybe poor OCR was to blame (e.g. 1744 looking like 1944) but it's something that could easily have been noticed and fixed if a human had looked over things now and then. It seems that has now happened; while I did find a couple of errant titles the vast majority were correctly dated (or at least, the vast majority of the ones said to be from the 20th century were; it could be that the reverse problem is occurring too). So these are really positive developments, and signs that NewspaperArchive is committed to improving its service. The bad news, however, is really quite bad, at least from my point of view. It seems that NewspaperArchive has run into copyright or permissions problems, because now none of the British titles it carries go beyond 1904 (which also means that a couple of them, Lloyds News and the Staffordshire Sentinel, have been dropped altogether; the Hackney Express and Shoreditch Observer has been added, but this is already in the British Newspaper Archive anyway). Previously they mostly extended into the 1910s or 1920s. For example, the single most useful title, the Daily Mail, used to be covered up to 1921, so you'd get Versailles, the Great War, the People's Budget, the dreadnought race, the beginnings of airmindedness... now you get, I don't know, the Taff Vale decision? So I doubt I'll be renewing my subscription to NewspaperArchive: there's just not enough stuff for me now. But given the great improvements NewspaperArchive has made recently, I'd certainly join up again if the coverage situation improves in the future.