We are kind of glad now that we waited with geocaching until Smarty had her own phone, so now she could take full ownership of preparation activities. She made an account on geocaching site, researched geocaching apps and downloaded two different apps on her phone. It proved handy to have both apps, because, as it turned out, the free official app only shows caches on easy terrain, and our hike included a steep climb that was clearly not coded as "easy terrain". Smarty's other app c:geo showed all caches that were not premium (those require a paid geocaching app) and was almost as good in navigating interface as the other app.
The good thing is that geocaching is quite popular where we live. The park where we hiked had literally dozens of caches of different sizes hidden along the trail that we took. We attempted to find four of them and succeeded every time even though one cache was quite hard to spot. Bigger caches contained little trinkets, and Smarty brought some of her own for exchange. Each cache has a log where we left our signature and date, and Smarty also logged her finds via an app. Overall, finding geocaches was a very fun experience that added some extra spice (and good 30 minutes) to our hike. Now Smarty can't wait to go again - unfortunately, we expect a lot of rain over the next week, so the next geocaching adventure might have to wait.
Have you tried geocaching?