Many people seem to use Tegaderm. I knocked my sensor and it became a bit unstuck but was still working so I applied Tegaderm over the sensor (with a circle of paper to cover the sensor, in case I wanted/needed to remove/change the Tegaderm) and it's held up well. Without the Tegaderm, I didn't feel I would be wise to shower as water would get under the sensor but, with the Tegaderm, it has been fine.
I've also read (Facebook Abbott Freestyle Libre) of many other products that are being used satisfactorily.