How do I persist in a meditation practice when my mind rebels and tells me I’m being boringly routine.

If you’re using this app, I would think that you came here with the intention of building a routine. If something is telling you that your routine is boring, I would challenge where that opinion comes from. Is that a core belief? Is it something you learned from media or another person, that having a routine is not spontaneous or makes a person boring? In the case that your core self is bored, there are many different types of meditation and you can switch it up every night — but still plan which you will do to save yourself the time it takes to decide. In the case that this belief was learned you can remind yourself that out of all the hours in a day that you spend awake, you only do your routine for maybe a couple of those.

A quiet space usually helps me focus, so that may help. If that doesn't, you can try to refocus your mind. It also helps to make sure you're paying attention to the guided meditation.