Actually, it's free for 24 hours – but I can't tell when that period started so just go grab it now.

As ever with these things, don't bother thinking about it. Grab it while it's free, ignore it or even delete it – and when you need what it does, there it is. Or you can re-download it for free. And you get updates for free. But only if you bought it during this free period.

I just went to check the details and discovered that I've done this before. I knew I had with a lot of apps – a year or two ago there was a massive spate of travel apps going briefly free and I nabbed the lot, have since used a couple too – but I found I'd done it with Readdle Printer Pro for iPhone too.

No idea when that was. But I don't believe I've ever used it. So this isn't a review, isn't a recommendation for the app per se, it's a recommendation that you take advantage of this chance to get a popular app and try it out.