Trello is awesome but when you need to manage cards between multiple boards, you can loose track of your cards. For example when you want to manage your work between a product backlog and a sprint board or when you delegated cards to a client board. Keeping track of the work is often a pain.
What it does
Card mirror for Placker is a Power-up that adds a button to your card. When you click the button, you select a board and a list, and it will create a mirrored copy of the card. Then, updates on the card will be synchronized with its mirror.
In case you use labels or lists to track progress, the labels or list will get updated accordingly.
It has advanced settings to go wild; instead of updating the card, the update can be recorded in a comment and you can set which attributes should be mirrored. You can even select different attributes for each of the two cards.(For example to capture card comments of a card on a master card).
The power-up depends on Placker.com which is a separate service that adds project management to Trello. In Placker you can also create mirrors between checklist items and cards, to automatically mark the items completed when the cards are done.
Users of the power-up will need an active account on Placker, they also need to export boards into Placker to make this work. The user can only mirror cards on boards that are already exported to Placker, there is a simple widget on the power up that helps the user import the board.
How I built it
I used the Placker backend and a lot of user input to define the key use cases. Then I used the excellent documentation that is available on creating Trello power-ups, with support from Bentley and Anthony from the Trello team to create the power-up.
Challenges I ran into
The complexity of the mirroring, and required performance to make sure that the updates are processed in real time. I had a lot of user input from the current Placker base and almost everyone uses mirroring slightly different. The biggest challenge was to freeze the scope and fix this.
Accomplishments that I'm proud of
The reactions when I show this over skype in a support call are amazing, it really looks like magic when you see it the first time. :)
What I learned
Card mirror for Trello is a spin-off from projects for Trello (another posted project) after I got a lot of reactions on this feature specifically, I decided to submit this as a separate power-up as the features in projects can be a bit overwhelming.
What's next for Card mirror for Trello
Card mirror does not yet contain Member and Label mirroring, also it does not yet mirror checklists/items on the cards. This turned out to be a bit too complex for this iteration.
The possibilities with card mirroring is huge, for example, to create 'list portals' where a list on a board can be linked to a different board that represents the stages (e.g. design, test), when you move a card from one list to another, it will create a mirrored card in the linked team board.