This is a proof of concept to see if I could make a Twitter app inside of Shortcuts. It uses Scriptable to handle the oauth authentication and Toolbox Pro to make a pretty menu.

It also uses an unpkg importer to save JS modules to iCloud Drive/Scriptable/modules. For more info, read this Gist

Create a new Twitter app and generate some consumer and access tokens to place in the dictionary at the top of the workflow.