Aspen's gradebook interface is tedious at best to use. So, I built a tool to make it easier to create assignments from spreadsheet data or from google classroom.
The tool is still in beta -- which is to say, I use it constantly, but I'm pretty much the only one using it.
To work around trouble with getting the google classroom API to work properly in a chrome extension, we use a google apps script web app to relay classroom data to our chrome extension.
As an added bonus, this tool has a toggle to make Aspen look a bit less ugly.
If you want to use google classroom integration, click on the Aspen Automator button and then click the button to authorize the google apps connection.
Google Classroom Integration
Go to your Assignments tab of gradebook and click "Import from Google Classroom." Note that imported assignments will begin with a 4-5 digit code that lets the automator identify google classroom assignments. This will make it harder to grade these assignments manually, but the whole point is that you're not planning to grade manually anyway.
Once you have assignments imported, you can import grades when you go to the "Scores" tab and choose "Import from Google Classroom".
CSV/Google Sheets import
Open up a google sheet.
Click on the "A" icon from Aspen Automator to copy the correct headers for entering either assignment data or grade data.
Enter the correct information into the columns, with one row per assignment or grade you want to import into Aspen.
Once you are done, choose the "A" icon again and choose "Send Assignments to Aspen" or "Send Grades to Aspen"
Open the grade tab (scores) or assignment tab in your gradebook and an import window will appear.