How can I KEEP my shower glass block window free of water spots. Is there something I can use as a repellent?

I can not squigi it everyday due to physical limitations. I am hoping that someone will come up with some kind of wax or water repellent that I can apply and then only have to clean the galss weekly or even every other week rather than every dayHow can I KEEP my shower glass block window free of water spots. Is there something I can use as a repellent?
RainX is a good suggestion, but having physical limitations myself, I find it a little difficult to apply because it is a creamy lotion that requires a little more work and effort than I am able at times to devote. I found a spray on application easier with a product called Glass Magic. It comes in a fushia pink aerosol can and it produces a seal on the glass that repells soap scum for quite a long time.How can I KEEP my shower glass block window free of water spots. Is there something I can use as a repellent?
Clean it with regular shower cleaner and afterwards apply a light film of Old English Lemon Oil. Sounds weird, but it's what alot of housekeepers use.
after it has been cleaned, a small amount of WD-40 will prevent water spots, and build up
Rainx. But only after is is clean. Reapply it every week.
Clean it with vinegar.
What about the stuff you can buy for your windsheild on your car. It repells water and makes it bead off.