GTrello is a GMail add-on, which adds Trello integration.

Project was created to solve single problem: gather all tasks in single place.
I'm heavy user of both Trello and Google tasks to schedule tasks,
I was lacking a feature to have them under one roof.

Currently add-on displays Trello Cards from list the name user provided on 'Token' screen from every starred board user is member of. This is actively developed and behavior will be customizable

I simply lost the grasp of many tasks I have on my GTasks and Trello boards, thus simple aggreagtion under one roof is a huge help for me.

Application is not published publicly.
In order to install, following setups must be made:

1. Install GTrello as GMail add-on
2. Enable Trello access
3. Authorize GTrello to Trello

Mind that the setup is not idempotent, multiple runs will yield multiple projects.
Add-on is installed as developer add-on

> git clone https://github.com/kiemlicz/gtrello.git
> npm install @google/clasp -g
> # run setup providing Timezone i.e. ./setup.sh Europe/Warsaw
> ./setup.sh Your/Timezone
> clasp push

To enable add-on, follow official guide
In short:

1. Navigate to AppScript GTrello project
2. Deploy -> Test Deployments -> Install

Somewhere along the setup or publish you might be asked to enable AppScript API which must be done. If not then navigate to GCloud, setup dedicated project and find Apps Script API -> Enable

To enable Trello API access, create new integration, name it GTrello

Once the add-on is installed:

• Authorize access
• then provide API key from Trello (GTrello power-up, API key tab) and follow authorization dialog. Copy token, close the window and paste token to GTrello add-on.
  Provide the Trello list name.
  All cards from all user's boards from that particular list will be displayed.

Simply after changes run

> clasp push

Alternatively, tasks can be kept only under Trello with some help of ifttt-kind of services, however they come with limitations like: time delay, a bit tedious setup, paywall

• Clasp is a tool used to develop AppScript locally, otherwise web interface must be used.
• Issue that made possible creating add-ons without requirement of selecting particular e-mails.