Costello: Costs for Trello
Update: Costello is now listed on Trello by default! You no longer need to follow the procedure below, just find it under Power-Ups in your board menu.
This is a Trello Power-Up which lets you add costs to cards and provides a sum of those costs as a board item.
To enable this Power-Up for your Trello boards, you'll need to go here:
Select the Trello team you want to add the Power-Up to. Note: You need to be an admin of the Trello team to add custom Power-Ups to it.
Now click the Create new Power-Up button. If this is your first time adding a Power-Up, you'll need to agree to a "Joint Developer Agreement" first. After you have done that, you just need to give your Power-Up a name, and paste this app's manifest url, https://webrender.github.io/trello-costello/manifest.json.
Click Save and it's time to celebrate
Now when you look at the Power-Ups for any board in that team, this Power-Up will be available. Enable it and you'll be able to set costs for cards when you open them. If you'd like to add functionality, you can fork this Glitch project and edit the source as you please.