Tracker means diary, not radar gun
In live music, a concert tracker is an app that records shows you attend: artist, venue, date, sometimes setlist, photos, and friends. It is closer to a journal than to flight tracking.
Ticket marketplaces sometimes borrow the word. If you cannot log 2017, it is not a tracker. It is a store.
The fields that matter
Minimum viable tracker: artist, venue, date. Useful tracker: rating, notes, setlist, who you went with. Radar is in the second camp, with UK Find so new nights enter quickly.
Stats and Wrapped are outputs. If the inputs are wrong, the year-in-review is fan fiction.
Pick the job
Want onsale pings? Use an alert app. Want a Letterboxd for nights out? Use a gig diary. Radar is the diary, with enough Find to live in the UK without five tabs.
Start free, log the last show you went to, and see if you open it after the next one. That is the only test that matters.