Regarding GPS interference, a GPS antenna is a receiver, not a transmitter. More GPS enabled devices around it will not affect performance, as they're all listening to the same frequencies. WAAS is also broadcast and received in a similar fashion and frequency, which is where you get down to Cat III levels of accuracy for Autoland.

As for bands, cell phones are sectioned to ~700-900 MHz and some small ranges above ~1700 MHz for VHF. VOR navigation operates between 108-118 MHz while GPS sits specifically at 1575.42 MHz (L1), 1227.6 MHz (L2) and 1176.45 MHz (L5) with WAAS and SBAS sticking close to those. From a VHF standpoint, a cell phone will not cause interference. I can also confirm this by goofing off with my phone while using an IFR4000 test set and watching the nav display indications in the flight deck.

Now, SHF is where things change a little bit. SHF is very directional and fairly short range. It will not make it inside or outside the metal tube of an aircraft very easily. Although the 5G cellular band is separated from the radio altimeter band, the Rockwell-Collins systems were receiving occasional interference from ground antennas during landing. Since the initial issue was discovered, they've patched the transceivers with better filtering (supposedly from just adding a LPF filter, which wasn't necessary before); and issued a service bulletin requiring the use of a newer model of antenna (which used to be optional. The 5 fleets I work on have all been updated or verified at this point.