I've been using the task-list-management app Things since 2009. It's far from perfect, but it's the only to-do-list software that I've managed to keep using for more than a month or so.
One of the things I like about it is that it has an iPhone version that syncs with the Mac version. But a few weeks ago, the iPhone version stopped working. It would start to sync, then get to a certain point and crash.
I sent email to their tech support people, requesting help. The guy who responded, Matt, did a really excellent job of providing support; I complain so much here about bad customer service experiences that I thought it was worth posting a note of praise.
Over the course of half a dozen emails and several weeks (my delays, not his), Matt was incredibly patient with me, despite my complaints, and very helpful, and friendly, and polite, and a couple of times he gave me detailed technical answers when I asked specific questions or made suggestions.
He knew exactly what the problem was: there's a bug that causes sync to time out under certain circumstances when your “Logbook” (the archive of checked-off and canceled tasks) is too big. (Mine went back five years, and had something like 10,000 items in it.) He told me a way to work around the problem: export the Logbook to a PDF. I use the Logbook for historical purposes, to figure out what I've done and when; unfortunately, the PDF export didn't include all of the info in the notes on items, so this wasn't sufficient for my purposes.
He told me that there were two other options: I could use an unsupported short-term fix (with the help of a third-party application), or I could create a separate copy of the Things database that contained only the Logbook, and then I could open that whenever I needed access to the Logbook. I opted for the first option; he guided me through using iExplorer to copy the database from a working device to the iPhone. Unfortunately, in the meantime I had tried various things I thought might work, leading to his approach not being workable. (I'm pretty sure it would've worked fine if I hadn't tried to fix things myself.)
So I asked about the separate-copy-of-Logbook option, and he sent me an amazingly good set of instructions. Step by step, precisely accurate, showing exactly what I needed to do, carefully setting things up in each step in a way that would avoid problems later. Really excellent tech writing.
I managed to still mess things up, by accidentally skipping the very first step. (Feel free to remind me of this next time I bemoan people's inability to follow instructions sequentially.) But I had a Time Machine backup of the relevant files, so I restored from backup and followed the instructions again, and this time everything went perfectly. And now Things works on all my devices again, and I still have access to all my old archived items when I need it.
So here's a public thank-you to Matt at Cultured Code. Way above and beyond the call of duty; very much appreciated.