The iOS app has been pretty good (if a bit buggy and slow), but the desktop web interface is so bad to the point that I haven't used it in over a year -- and I use myfitnesspal daily.
I've definitely had the app perma-crash on me recently, where the only way to get out of the boot-then-crash loop was to delete and reinstall it.
It also fails at the iOS quick access menu about 80% of the time. e.g. you hard-press the app icon, go to "log food" and it goes back to the home page. Or you do the same for "scan barcode" and again most of the time it opens the app and sends you to the home page again. This has been the case for months.
