For Android:

1. Google Keep: A versatile note-taking app that allows you to create sticky notes, reminders, and lists.
2. Microsoft OneNote: A robust note-taking app that offers sticky note functionality among other features.
3. Sticky Notes Widget: Specifically designed for creating sticky notes on your home screen.

You can download these apps from the Google Play Store.

For PC:

1. Microsoft Sticky Notes: Comes pre-installed with Windows and allows you to create and manage sticky notes easily.
2. Simple Sticky Notes: A lightweight application that lets you create customizable sticky notes on your desktop.
3. Notezilla: A feature-rich sticky notes app with options for syncing across devices.