Reading Apps are specialized mobile apps allowing parallel reading of a text and related material such as translations, commentaries, or audio. The content is searcheable and the resources are linked at the sentence level. Here are a few examples:
Prayer collection with multiple translations (download for Android):
Shantideva’s Way of Boddhisattvas with multiple commentaries synced at the sentence level (download for Android):
37 practices of the Boddhisattvas with an oral commentary synced at the sentence level: