My smart* phone's keys* are on the touch screen, they don't react to fingernails so you have to use a fingertip. How wide are the keys? How wide is a fingertip? It might react to the key you're trying to press, or it might react to the one next to it, it might not react at all, or it might react to a key in a completely different place altogether. If you turn the phone sideways the buttons get slightly bigger, but then you can's see much of what you're typing.
The predictive text isn't so bad, instead of the dumb phone's single suggestion it gives a row of them, so if you're typing hammer it'll suggest words with the letters you've managed to type in so far (ham, hamper, hammock, hammer...) which you press to finish the word off if it's on the list, starting off with your typo which if you hit the phone will add to the dictionary forever. It can also cope with these things ŠĐČĆŽ (unlike pc spell checkers) which I'm sure you'll find a use for...
I use few apps on mine, the one I seem to use most of all is the super task killer which I regularly use to kill off all those apps the phone's started up all by itself without asking and which just sit there draining the battery. Oh, and there's an app to see what the solar panels are up to

And tapatalk of course, which I get to use whenever I'm near an open network (which is mostly some cafes these days, there used to be more but I think they finally figured out network encryption in places like the clinic & the hospital, restaurants are still open usually but mostly don't seem to have an actual Internet connection). I should probably get an internet package (or whatever they call it) but I can't do that on prepay here so it involves paying a bill every month, which I don't want to do in case I accidental leave it connected overnight and get a bill for eleventy billion weasels.