There are two types of MetaTrader indicators: 

• Built-in MT4 indicators: this group includes pre-installed indicators like moving averages, MACD, ATR, RSI, among others.
• Custom MT4 Indicators: are programs developed independently in MQL4 and they aren’t part of the standard MT4 installation package.

Desktop MetaTrader

For built-in MT4 indicators, in the process of installing MT4 you should see that the indicators files will be downloaded and installed as well automatically.

After you complete the MT4 installation, make sure to check the indicators directory in the navigator window of your MT4 terminal

In addition, if you need to modify or you want to remove one of the built-in indicators, you can always follow these steps to access the files in your computer:

• Go to your File tab and move down the menu to the “Open Data Folder” selection, this will trigger a new screen.
• Then, you can navigate to the folder that says “MQL4”. In that folder, you will find the next subfolder named “Indicators”.
• After that, you will see the list of all the MT4 indicators files that were pre-installed on your computer. Also, you will notice that all of them come with a couple of files in .ex4 and .mq4, which are the valid formats of MT4 indicators.
• If you perform any changes, you will need to restart your MT4 platform as well.
• Check the indicators directory in the navigation window to verify the changes.

Mobile MetaTrader 

To add the built-in indicators to a Mobile MetaTrader application press, or tap, anywhere on the chart screen. 

After that, a new round menu will pop up on which you may select a “Functions” option. 

After selecting the “Functions” option a list of all the available predefined and built-in indicators will pop up for you to select the one you need.