Just a quick word on mobiles with quirky faults like WIFI going off apps not running properly.
Over the last few months I have had a problem with a couple apps not working properly on Android phone. Did all the usual things reboot the phone and reinstall the app but this did not fix it. While browsing my way around the phone I found that the SD card appeared to be full abut it was not.
A quick format of the card went well or so it seemed but no it was still reporting full with a bit of data on. Fitted a new SD Card and bobs you uncle everything was working correctly no apps problems.
Next Problem was again an apps problem but this time the WIFI would not reconnect to the router when the lease had run out. Again changed the card and again all fixed.
Moral of this story check your SD Card