Make good cocktails, bring to me and refill, take my truck out for a wash and smite agents with IQs under 70 that seek to disturb me.

We are up to our earlobes in apps at this point in time, really . . .

Honestly I never found any Real Estate software very useful during my career as an agent or Broker BUT if I did I would want it to remind me of anniversaries and holidays. I would like it to have a feature asking if I would like to print a mailing label along with said reminder.

Software that would blow up the phone of a spam caller and/or robo-dialer!  

A CRM that not only included the features of new technology such as group text and email with embedded video creation but also included legacy marketing of letter and postcard creation for direct mail.

Reliability.

How about one that works!

What is the software trying to accomplish?  There are many software types out there from CRM to dialers to web servers to email clients.

I would like a feature that makes it mandatory for a seller to make their home available should it be on the MLS and scheduling be a mandatory feature.

Lyn Sims has the right idea. And, if I may add, one that can be adapted to specific needs the agent may have. See the suggestion by Bob "RealMan" Timm for example.