Dax Studio provides full intellisense support
Note that it’s based on the best practice of always prefixing columns with the tablename and never prefixing a measure with a table name. So if you type ‘table name’[ you will get intellisense for all the columns in the ‘table name’ table. But if you just type [ you will be presented with a list of all the measures in the model.
It will list both Functions and Keywords: