FWIW (more years in a Leaf than I care to remember), I've only ever really used ZapMap for working out what chargers are broken (I have PlugShare installed but I don't think I ever used it). And then - in rough order of ease of use, though I usually just had to go with whatever was closest - I had/have the following apps:
InstaVolt (though I usually just used a contactless card)
Polar Plus (very cheap rapids, if they're working, especially as I get free membership through Ovo's EV tariff)
PodPoint (generally slow chargers)
Charge Your Car (ditto)
Electric Highway (absolute pain the arse - get the app going, stand in the rain trying to scan a QR code, try to remember which credit card is valid...)
GeniePoint (sometimes, if it's possible, even more frustrating than Electric Highway)
Naturally, since getting the Tesla, the Leaf is now relegated to pootling around town and quick trips to the coast, and it's been (occasional) superchargers and home charging all the way. But some of the above apps/services might help if things go belly-up and you're in a supercharger black hole...