Perfect Chess Trainer::Appstore for Android

Chess opening training - Chess Tempo opening trainer

Catastrophes & Tactics in the Chess Opening - Volume 3: Flank Openings: Winning in 15 Moves or Less: Chess Tactics, Brilliancies & Blunders in the Chess Opening (Winning Quickly at Chess): Hansen

PPT - Analysing your own games

Chess Openings Trainer Pro - Apps on Google Play

Opening Repertoire Trainer

Lichess just added opening training (in addition to their tactics trainer). Check it out! : r/chess

Catastrophes & Tactics in the Chess Opening Workbook - Vol 1: Indian Defenses: Tactical puzzles to help exploit opportunities and avoid disasters in (Winning Quickly at Chess Workbook Series): Hansen, Carsten

User Guide Chess Openings Trainer

FRITZ TRAINER - The Surprising Janowski Variation (3a6) in the Queen's Gambit Declined - Fabien Libiszewski

Chess Opening Trainer App Price Intelligence by Qonversion