California Counties - Locations of All 58 Californian Counties on the CA Map and Their County Seats

I lived for a year in Alameda county. I've been in Orange county several times. I have visited many California's national and state parks. Still I have had no idea how many counties are in CA (the right answer is 58). As usual, the best way to learn all those 58 counties, their county seats and locations on the California map is to create an app about them. Testing the app, I'd have a plenty of time to browse them all from San Diego in the south to Crescent City in the north, from the famous CA ocean coast to Mohave desert and the Sierra Nevada mountains.