Monkkee is so secure that the entries can be read only by you. If you lost the password it is lost forever. No one has access to even your password. It provides client side encryption i.e the entries are encrypted even before they are transferred to the server. It is easy to use. You can categorize your diary entries using tags.
Based on our record, Phabricator seems to be more popular. It has been mentiond 3 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
My company has used Phabricator, which is an alternative to Azure Devops, for about 5 years. A few days ago they announced that the project won't be maintained anymore, so we are looking into alternatives. We have around 50 devs+product folks that use Phabricator at the moment. Source: about 3 years ago
You also mention Gitlab is close to what you would like - maybe Phabricator is even closer: https://phacility.com/phabricator/. Source: about 3 years ago
Https://phacility.com/phabricator/ I think checks most of those boxes, maybe all. Source: about 3 years ago
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