I'm trying to get more flexible, but I find going through other peoples stretch routines boring. My best times stretching have been like, a saturday morning watching a soccer game.
So: a little minisite that just refreshes a random stretch recommendation: one for shoulders/back, one for legs/hips.
I've got this at https://mattkirkland.com/stretch and a little app icon so I can add it to my phone's home screen.
I'm adding new stretches as I think of them or enjoy doing them at the gym.