This remains the only way to control app usage. After 5.0 apps can no longer turn other apps on or off data. In fact, the system Data Usage feature can no longer either. Verizon says Family base is the only way to turn off data completely at specified levels. In other words, those of us who used My Data Manager or other data monitoring apps can no longer set a daily limit nor an alarm for other increments where used to, the app could turn data off in case an app was running wild.
Unfortunately, some apps only work when you/i/we are connected to mobile network. So those apps will use up data from your/my/our monthly data allotment.
All the apps i have on my phone (G3) work just fine on wifi.
Once in a blue moon i'll turn on mobile network, only because i need access in real time. Such as, when it doesn't make sense for me to walk around looking for a free wifi hotspot.