Ereader is great for reading in idle moments. Unfortunately mine lives at work currently (for reading scientific papers). At one point I read while my kids were listening to an audiobook in the evening. I could get a nice amount of extra reading done that way even though it takes some extra concentration.
Usually I read when the kids are in bed, but it’s a bit hard when there are other competing things to do like talking with my partner or watching something. I’m trying to learn from my daughter who just reads during any spare moment in the day, and she has read so much this spring.
I use the strictly offline Book Tracker app on my iPhone. I don’t really care about reviews or the social features, I just want an overview and some stats about my reading.