Golfshot is free, gives me yardages, hole overview and tracks the group score.
It’s free web portal is good for a nice review of past rounds and the stats are simple, well focussed and helpful. It even gives me a rough idea of my handicap, it is nice to see little cuts when you play well!
The Apple Watch companion app is a great quick reference and means I can leave the phone in the bag when playing shorter courses.
What more could anyone want from a free app?
The top tracer app is Ok too, still getting used to it but it’s helpful.
Weather wise I use Dark Sky which has more than paid for itself with the alerts, live radar and next hour rain forecast, the alerts have saved more than one BBQ from a surprise washout.
Dont forget a shout out to those who dont take their phone onto the course, like most on here the only golf related apps i use are for the club, or youtube if watching courseflovers counts...