A friend of mine’s wife needed a grab bar, and he asked me for assistance. His concern was that he couldn’t find the studs in the bathroom wall due to the heavy stone tiles in his shower. Installing a grab bar is a simple process and it is possible, in certain circumstances, to use traditional wall anchors to do the job. See photos below.

Here I’m marking my parameters. I’m using tape instead a pencil as tape doesn’t leave any marks.
This is my bottom mark. Note that I’m placing the screws over the large tiles instead of the weaker small tiles.
Drilling my initial hole.
Using a long level to make sure that the bar is straight.
After the holes are drilled I placed the anchors. I then cut off their collars with a pocket knife and a hammer.
The bar is very secure!
My friend’s shower is now safe and ready for his wife.