Stand-up showers are a bit annoying. I find they have a tendency to build up mildew and mold like nobody's business, this is especially true of the glass variety. While frequent scrubbing is one way to keep these suckers clean, I have a few extra tips to make it a little easier.
1) Keep the door open.
Right after you finish your shower, keep the door of the shower open. Closing it tends to make it more challenging for your shower to dry out. Moisture breeds mold and mildew.
2) Keep the fan on.
If there are no windows to the outside world, then I recommend keeping the fan on for quite a while, several hours at least. This keeps the air circulating and lets the bathroom dry out faster. As you probably guessed by now, moisture breeds mold and mildew.
3) Keep the bathroom door open.
Don't seal your bathroom in after you take a shower. Keep the air circulating so the remaining moisture can evaporate because this is yet another mildew breeding factor and... moisture breeds mold and mildew.
Rather than using fancy, toxic shower sprays, just let your bathroom dry out the natural way - with air circulation!