Gleek
If you think in text, Gleek is faster than any drag-and-drop canvas, and at $6.95 a month it undercuts the diagramming tools people usually reach for. The cost of the approach is its own syntax — not Mermaid, not PlantUML — so what you write here stays here.
Pros
- Its own terse syntax covering flowcharts, UML, ERD, Gantt and user journeys
- AI chat drafts the syntax when you do not know it
- Git connection, shareable links and custom themes
- Usable free tier, and Premium at $6.95/month or $58.40/year
Cons
- Proprietary syntax rather than Mermaid or PlantUML, so diagrams are not portable
- Free tier caps you at five files, 40 objects each, and PNG export only
- No API and no desktop application