There are a clients that make this convenient. Toot! on iOS has one of the more delightful UI innovations I've seen recently in the form of a wheel in the corne

There are a clients that make this convenient. Toot! on iOS has one of the more delightful UI innovations I've seen recently in the form of a wheel in the corner that you can rotate to flip between what looks like different copies of the app, each individually themed and associated with a different account.