Power-Ups allow you to bring additional features to your boards and integrate your favorite apps right into Trello. They can pull information and data from outside services directly into Trello, giving you a clear perspective on your favorite tools for work. Power-Ups will help you meet your unique Trello needs!
Here I present you the top essential Power-Ups for May 2020

Calendar
Visualize Trello cards in a calendar view.
4,000,000+
Enabled on more than 4,000,000 boards
❤️ Staff Pick
A favorite of a Trello employee
For More Information: https://trello.com/power-ups/55a5d917446f517774210011

Custom Fields
Add custom fields like text, numbers, checkboxes, dates, and dropdown lists to cards.
1,000,000+
Enabled on more than 1,000,000 boards
❤️ Staff Pick
A favorite of a Trello employee
For More Information: https://trello.com/power-ups/56d5e249a98895a9797bebb9

Google Drive
Access your Drive files for a project directly from its card, or create and attach new Drive files to a card.
1,000,000+
Enabled on more than 1,000,000 boards
For More Information: https://trello.com/power-ups/55a5d916446f517774210006

List Limits
Set a limit on your lists to highlight them if the number of cards in it passes the limit.
50,000+
Enabled on more than 50,000 boards
For More Information: https://trello.com/power-ups/5c2462c384ab8949b1724a20

Map
A whole new way to see your board. Add locations to cards and view them on a map.
50,000+
Enabled on more than 50,000 boards
For More Information: https://trello.com/power-ups/5ad892c30b141641d32919bf

Slack
Connect your communication and collaboration apps so that no ideas or tasks fall through the cracks.
250,000+
Enabled on more than 250,000 boards
For More Information: https://trello.com/power-ups/55a5d917446f51777421000a