I wanted to build a simple webapp from scratch. No library, no API, nothing. I feel this makes me understand more what goes on when you use "helper" products, which I intend to learn soon. I used PHP, MySQLi, HTML, CSS to build a simple proof-of-concept house cleaning management webapp for roommates to use. Rooms to be cleaned are assigned to a person in the apartment and each room has associated chores. Roommates all use the same account under the same "house_name". Each house has its own rooms, people and chores all stored in a MySQLi database
To me, interfacing with the database and displaying the appropriate content on the screen was a big accomplishment because I had never used PHP nor MySQLi beforehand. The data generated on the chores page is dynamically generated based on the content from the database.
Although with the current version, it is pretty limited since the user cannot really well manage the list of tasks and rooms, it still illustrates the ease of use of the webapp.