It’s quite easy to turn MiAffirmations into a meditation tool. You record your mantra into an existing playlist or create a new playlist, turn repeat on and choose a relaxing and/or meaningful background music.
Note that the free version has 3 predefined playlists and you cannot create new ones. This restriction does not exist in the paid version—for more info see the version comparison table.
Obviously, this technique would work only with mantras that have a meaning. It’s not useful with mantras that do not have any specific meaning (but are designed to be mere concentration tools).