[Utah-astronomy] astro apps

Thanks for the recommendations.  Several people named Skeye or Skyeye, so it got downloaded first.  HOLY COW!!!   A full planetarium program for free!!! and I paid hundreds of dollars for The Sky for my laptop.  The only problem is the size of the screen - I feel you pain Chuck!!.  But the view can be enlarged (call it zoom in) with the flick of two fingers.  It's going to take me weeks to get the hang of it.  Is Skymap Pro and Sky Safari similar?  What is Skywalk and Astromist?  Someone mentioned an app that calculates sunrise/sunset and astronomical twilight awhile ago.  Does anyone recall the name of that app? Thanks to all who responded :)