welcome to building apps with react
native an app is an abbreviation for
application when you hear the word app
you may think about phone apps such as
Instagram and snapchat but really an app
is any program that you write and run
react is written in JavaScript and is
used to make webpages load faster and
run smoother react to native takes these
applications and transfers them to a
mobile application in order to have a
similar experience but on a smartphone
or a tablet a number of apps today use
react native including ubereats
Tesla Instagram Skype and more the apps
we are writing on code HS will actually
run through another app called Expo Expo
is an app that makes it really easy to
run and test the programs we have
written in react native this means we
don't need to download an app and update
it every time we make a small change to
our program in a moment the first
exercise will be downloading the Expo
app you'll find this app at Expo IO or
on the Google Play Store or Apple App
Store
once Expo is downloaded it will work
slightly differently based on your phone
type if you're using an iPhone to view
an app all you need to do is open your
camera and point it out the QR code on
the page a notification will pop up on
your screen and ask you if you want to
open the app and expo click this and
you'll be brought to the expo app if
you're using an Android open the expo
app in order to scan the QR code to see
your app appear on the screen click the
green Run code button in the editor any
time you make a change to your code just
click this button to refresh the app on
your phone move on to the next exercise
to download the expo app