# Level 3 - Professional

**Level 3 - Professional** Smart Apps are customizable using Flows, and offer access to advanced features like [integrations](https://manuals.dialox.ai/store/skills/integrations), [planner](https://manuals.dialox.ai/store/skills/planner) capabilities, and [knowledge bases](https://manuals.dialox.ai/studio/ai/knowledge-bases).

## Planning & Scheduling Apps

The planner skill allows users to reserve time slots in your calendar. The [Appointment Planner](https://manuals.dialox.ai/store/marketplace-apps/level-3-professional/appointment-planner) App uses chat features to schedule specific appointment times sent directly to your calendar. The [Callback Planner](https://manuals.dialox.ai/store/marketplace-apps/level-3-professional/callback-planner) App is a phone implementation that lets users choose a window of time in which you will call them back to follow up, leaving a callback note with relevant information.