We're now so reliant on smartphones for so much of our day-to-day lives that everything can grind to a halt when something goes wrong with them - from keeping in touch with our nearest and dearest to trying to get a payment through on a banking app.
Fortunately, today's smartphones - with their limited file system access, carefully guarded app stores and touchscreen interfaces - are a lot easier to troubleshoot than laptops, car engines or cloud services, so you don't have to be a technical expert to work out a fix.
In fact, Android comes with a set of troubleshooting tools that can be used to solve almost any problem: essentially, you're going to reset the app you're having trouble with, or reset the entire phone, and this fresh start should theoretically wipe your issues away.
However, the same can't be said if you smash your screen or drop your non-waterproof phone in the sink - if you've got a faulty hardware problem then you're going to have to consult the experts at the local repair shop.
If you lose your smartphone, or it gets stolen, then make sure you check out our guide on how to survive when your smartphone goes missing.
For everything else, this guide should help.