I just saw on my iPad that Sony has issued a new version of the PlayMemory Mobile app. on the 26th October. Among the new features :
Easier connection to the camera with a QR code.
Improvements to the remote shooting app.
The remote app. inside of the camera needs to be updated to version 4.0 but it isn't yet available; last version for the moment is 3.3 and was issued back on the 30th July 2015.
Here is the link to the iPad app :
PlayMemories Mobile par Sony Corporation https://appsto.re/ch/uBhkD.i
I assume that Android users will get a similar update.
Here is where you can upload cameras apps to your camera : https://www.playmemoriescameraapps.com/portal/