Interaction with a user is one thing but what will happen if a user clicks this button? And how to show an error message once users forget about providing required data? You won’t do much without logic in your app. And that’s what PowerApps functions are for. Controls, properties, and functions are PowerApps bread and butter. Without knowing them you’ll be like a kid in the dark.
There are 155 functions, and they are fully described here. In the documentation, each function description contains a note of what it does, when to use it, required arguments, and some usage examples. And to be honest I never use all of them. But the below list is really worth those 30 minutes to check them in the documentation.
Protip: Some functions are unknown even to those who builds PowerApps professionally. These professionals waste a ton of time to make workarounds for what I’m solving in a minute. Some of those functions: User, Param, Language, HashTags,ColorFade, PlainText. Make sure you know them 🙂