The large brush and small brush with a wiper blade (on the right) can handle grout, plumbing fixtures, shower door tracks, and other small-scale crevices.
Promising review: "Angled handles get your hands up and out of the way. The handles are bigger and grippier than a toothbrush. The larger brush has pretty stiff bristles, which are great for heavy scrubbing without scratching. The smaller brush has tapered softer bristles on one end (good for cleaning in tight areas), and the rubber nub on the other end of the smaller brush is surprisingly good for cleaning in tight areas. I replaced the four toothbrushes in my cleaning kit with these." —jfb
Get them from Amazon for $5.99.