On this web page you can load many sketches. Use the Load Sketches button on the left, and select as many sketches as you like from a folder on your computer.
Once you have loaded sketches, a list of sketch names appears on the left. Below each sketch is a Utility menu on the left and a New Page button on the right. You can:
Drag the names to change their order.
Drag a name to the trash to delete that sketch.
Drag a name to "Clone" to duplicate that sketch.
Click a name to scroll that sketch into view.
Click New Page (beneath the sketch) to add a page.
Use the Utility menu to upload or download a sketch.