Kept it going for a while, making sure to take a day off once a month to avoid building another stressful streak. But I kinda got to the end of its usefulness and wandered off to other things.
Just started learning Spanish and I thought about firing it up again but the app is such a mess these days I actually can't face it.
Edit: Remember getting rid of the streak doesn't actually lose your "progress" in learning the language, which is presumably the important part. It's just a meaningless number. You can do it!