Whilst creating PowerApps, I found came across the below content from Microsoft. A complete index of PowerApps formulas. Formulas combine many elements, links back to Microsoft material included.
Abs – Absolute value of a number.
Acceleration – Reads the acceleration sensor in your device.
Acos – Returns the arccosine of a number, in radians.
Acot – Returns the arccotangent of a number, in radians.
App – Returns information about the currently running app, such as which screen is currently displayed.
Asin – Returns the arcsine of a number, in radians.
Atan – Returns the arctangent of a number, in radians.
Atan2 – Returns the arctangent based on an (x,y) coordinate, in radians.
Average – Calculates the average of a table expression or a set of arguments.
Back – Displays the previous screen.
Blank – Returns a blank value that can be used to insert a NULL value in a data source.
Calendar – Retrieves information about the calendar for the current locale.
Char – Translates a character code into a string.
Clock – Retrieves information about the clock for the current locale.
Coalesce – Replaces blank values while leaving non-blank values unchanged.
Collect – Creates a collection or adds data to a data source.
Color – Sets a property to a built-in color value.
ColorFade – Fades a color value.
ColorValue – Translates a CSS color name or a hex code to a color value.
Compass – Returns your compass heading.
Concat – Concatenates strings in a data source.
Concatenate – Concatenates strings.
Connection – Returns information about your network connection.
Count – Counts table records that contain numbers.
Cos – Returns the cosine of an angle specified in radians.
Cot – Returns the cotangent of an angle specified in radians.
CountIf – Counts table records that satisfy a condition.
CountRows – Counts table records.
DataSourceInfo – Provides information about a data source.
Date – Returns a date/time value, based on Year, Month, and Day values.
DateAdd – Adds days, months, quarters, or years to a date/time value.
DateDiff – Subtracts two date values, and shows the result in days, months, quarters, or years.
DateTimeValue – Converts a date and time string to a date/time value.
DateValue – Converts a date-only string to a date/time value.
Day – Retrieves the day portion of a date/time value.
Defaults – Returns the default values for a data source.
Degrees – Converts radians to degrees.
Distinct – Summarizes records of a table, removing duplicates.
Download – Downloads a file from the web to the local device.
DropColumns – Returns a table with one or more columns removed.
EditForm – Resets a form control for editing of an item.
EndsWith – Checks whether a text string ends with another text string.
Errors – Provides error information for previous changes to a data source.
EncodeUrl – Encodes special characters using URL encoding.
Exit – Exits the currently running app.
Exp – Returns e raised to a power.
Filter – Returns a filtered table based on one or more criteria.
Find – Checks whether one string appears within another and returns the location.
First – Returns the first record of a table.
FirstN – Returns the first set of records (N records) of a table.
ForAll – Calculates values and performs actions for all records of a table.
GroupBy – Returns a table with records grouped together.
HashTags – Extracts the hashtags (#strings) from a string.
Hour – Returns the hour portion of a date/time value.
If – Returns one value if a condition is true and another value if not.
IfError – Detects errors and provides an alternative value or takes action.
IsEmpty – Checks for an empty table.
IsMatch – Checks a string against a pattern. Regular expressions can be used.
IsNumeric – Checks for a numeric value.
IsToday – Checks whether a date/time value is sometime today.
Language – Returns the language tag of the current user.
Last – Returns the last record of a table.
LastN – Returns the last set of records (N records) of a table.
Launch – Launches a web address or an app.
Left – Returns the left-most portion of a string.
Len – Returns the length of a string.
Ln – Returns the natural log.
LoadData – Loads a collection from PowerApps private storage.
Location – Returns your location as a map coordinate by using the Global Positioning System (GPS) and other information.
LookUp – Looks up a single record in a table based on one or more criteria.
Lower – Converts letters in a string of text to all lowercase.
Max – Maximum value of a table expression or a set of arguments.
Mid – Returns the middle portion of a string.
Min – Minimum value of a table expression or a set of arguments.
Minute – Retrieves the minute portion of a date/time value.
Mod – Returns the remainder after a dividend is divided by a divisor.
Month – Retrieves the month portion of a date/time value.
Navigate – Changes which screen is displayed.
NewForm – Resets a form control for creation of an item.
Now – Returns the current date/time value.
Param – Provides access to parameters passed to the app when the user opened it.
Parent – Provides access to a container control’s properties.
Patch – Modifies or creates a record in a data source, or merges records outside of a data source.
Pi – Returns the number π.
PlainText – Removes HTML and XML tags from a string.
Proper – Converts the first letter of each word in a string to uppercase, and converts the rest to lowercase.
Radians – Converts degrees to radians.
Rand – Returns a pseudo-random number.
Refresh – Refreshes the records of a data source.
Remove – Removes one or more specific records from a data source.
RemoveIf – Removes records from a data source based on a condition.
RenameColumns – Renames columns of a table.
Replace – Replaces part of a string with another string, by starting position of the string.
Reset – Resets an input control to its default value, discarding any user changes.
ResetForm – Resets a form control for editing of an existing item.
Revert – Reloads and clears errors for the records of a data source.
RGBA – Returns a color value for a set of red, green, blue, and alpha components.
Right – Returns the right-most portion of a string.
Round – Rounds to the closest number.
RoundDown – Rounds down to the largest previous number.
RoundUp – Rounds up to the smallest next number.
SaveData – Saves a collection to PowerApps private storage.
Search – Finds records in a table that contain a string in one of their columns.
Second – Retrieves the second portion of a date/time value.
Set – Sets the value of a global variable.
ShowColumns – Returns a table with only selected columns.
ShowError – Displays an error message to the user.
Shuffle – Randomly reorders the records of a table.
Sin – Returns the sine of an angle specified in radians.
Sort – Returns a sorted table based on a formula.
SortByColumns – Returns a sorted table based on one or more columns.
Split – Splits a text string into a table of substrings.
Sqrt – Returns the square root of a number.
StartsWith – Checks if a text string begins with another text string.
StdevP – Returns the standard deviation of its arguments.
Substitute – Replaces part of a string with another string, by matching strings.
SubmitForm – Saves the item in a form control to the data source.
Sum – Calculates the sum of a table expression or a set of arguments.
Switch – Matches with a set of values and then evaluates a corresponding formula.
Table – Creates a temporary table.
Tan – Returns the tangent of an angle specified in radians.
Text – Formats a number as a string for display.
ThisItem – When in a gallery or form, returns the data for the current item from the container.
Time – Returns a date/time value, based on Hour, Minute, and Second values.
TimeValue – Converts a time-only string to a date/time value.
TimeZoneOffset – Returns the difference between UTC and the user’s local time in minutes.
Today – Returns the current date/time value.
Trim – Removes extra spaces from the ends and interior of a string of text.
TrimEnds – Removes extra spaces from the ends of a string of text only.
Ungroup – Removes a grouping.
Update – Replaces a record in a data source.
UpdateIf – Modifies a set of records in a data source based on a condition.
Upper – Converts letters in a string of text to all uppercase.
User – Returns information about the current user.
Validate – Checks whether the value of a single column or a complete record is valid for a data source.
Value – Converts a string to a number.
VarP – Returns the variance of its arguments.
ViewForm – Resets a form control for viewing of an existing item.
Weekday – Retrieves the weekday portion of a date/time value.
Year – Retrieves the year portion of a date/time value.