Contact
Noomachy DevTracker is built by Kode Foundry. One address reaches a person for all of the below, and it is read by a human rather than a ticket queue.
Support
Something generated badly, a repository that will not connect, a day that came back empty when it should not have. Include the date and the repository and it can be traced.
Billing
Invoices, plan changes, refunds, and anything a card statement raised. Subscription and payment details are held by the payment provider rather than here, so a card number is never something to send by email.
Security
Report a vulnerability to the same address and it is treated as the first thing of the day. Please describe what you found rather than acting on it against other people's accounts, and give a reasonable window to fix it before publishing.
Your data, and removing it
Ask for an export or a deletion and say which account it concerns. Disconnecting GitHub in the app revokes the connection immediately; deletion of what was already generated is a request to this address.