I have a Nexus 5 MuliROM with a FFOS 3.0 nightly installed. I've updated to obtain the spark apps. I'm trying to obtain the developer mode. Via WebIDE I switch to yes ADB is root and Unrestricted DevTools priveleges but I still can't use spark apps. How can I do it without loosing my data?

Here is the solution given by @DRS himself on #b2g of irc.mozilla.org :

drs you can still fix this, though drs there are prefs at the top of that page: https://developer.mozilla.org/en-US/...ttings_enabled drs you can just set those manually Thatoo how do I set them? Thatoo from WebIDE? Thatoo I found all except dom.apps.developer_mode Thatoo neither in preferences nor settings of this hardware drs you have to add that as a pref Thatoo cool, it works Thatoo thanks