AnkiApp lets you put multiple decks into folders and study them together.
To add a deck to a folder, from the Deck screen, open the menu, then select "Edit Deck".
Then choose "Folders" section to add the deck to a folder (or multiple folders).On the home screen, "Chinese" now appears under the "Folders" section.
When you select the folder, you're taken to the folder review screen, which lists all decks and options for reviewing.
From here, you can review all decks in the folder, or select individual decks to visit the Deck screen for one of the decks you see.