Medita chess enables you to practise playing any of the Encyclopaedia of Chess Openings as white or black by guiding you through each move. All ECO codes A00-E99 are available.
You can play against the Stockfish engine as an alternative to the built-in engine, so for example, you could see how Stockfish responds as black after you open with the Sicilian Accelerated Fianchetto, or have Stockfish play white and open with the Ruy Lopez Exchange against you. Medita chess is available as both an Android app and a PC desktop application.

Features:

Play against Stockfish, Medita, Ethereal and any other engines that support the Open Exchange format.
The playing strength can be adjusted at any point by dragging the slider. This adjusts the number of moves the computer will look ahead. I recommend using values of around 4-6 on a desktop PC and 2-4 if running on a phone/tablet.
Practise any opening from the Encyclopaedia of Chess Openings with each move highlighted for you.
Save and load game position, or load PGN.
Analyze position using "Analyze This" app (needs to be installed separately).
Wear OS app also available.