SimzzDev just released a new Mango app for Windows Phone. It is called Reminder Tile. Reminder Tile uses the new live tile functionality in WP7.5 to create a flipping tile on the home screen. You type your text, and choose a color. The live tile takes the first few words and puts them on the front side, with the Reminder Tile icon, and the back side shows the full note.
Reminder Tile is provided free of charge and has just one advertisement at the bottom of the page. You can download it here: