There are some of the free and most popular tools designed for digital marketing .
These are-
1. GOOGLE ANALYTICS-
through which one can see the demographics ,age,gender,area ,and such other data from time to time on how many people have engaged to their content
Very useful tool in marketing planning ,startegy developmemt,product development,targeting the right audience,building retention etc.
2.KEYWORD PLANNER -
It helps in identifying proper keywords for product or service or even for personal branding to reach the right audience .
3.Alexa
4.RANK WATCH -
To know on what rank your page stands ,giving competitive edge and idea from your competitors.
5.HOOTSUITE -
To pre plan and post your content on particular time for that you can use it .
Other tools are
A .MAILCHIMP
B.BUZZSUMO
C.KISSMETRICS