@Bmosbacker, these are relevant questions. I started practicing meditation way before cell phones, so learnt a lot from books and email groups. (Anyone remember Majordomo lists? 
)
As life happened, young kids, increased responsibilities at work etc, I fell out of the habit for a long time. I used a guided meditation app to help me get back (Headspace) and learnt several valuable new tricks during the months I maintained the subscription. Having some prior experience never hurts, but the ease of access to quality guidance right in my phone was really valuable to me.
Now I mainly use the timer for unguided sessions, placed on the floor behind me. There are plenty of other timer apps that will perform the same function, but hearing the sounds of the starting bell, interval bells and ending gong (all user configurable) really adds a bit of ceremony.
I realize I am firmly back on “grasshopper” level, and intend to follow additional guided sessions as my habit evolves.