- Osaka Map Puzzle
- OSC Blobs – Tapioca Toys
- OSC State – Tapioca Toys
- Oscar Adventure
- Oscar Collects Coin
- Oscar Winners Trivia
- Oscar's Bubbles
- Oscar's Treasure Hunt
- Oscar's Turtle Reef
- Oscar's Turtle Reef Premium
- Osipostales
- OSM Polyphonique
- OSM Transfer: Scout List
- Osman Gazi
- Osman Ghazi Warrior Legend
- Osman Ottoman Empire Warrior
- Osmanlı Bilgi Yarışması Oyunu
- Osmanlı Eğitici Tarih Oyunu
- Osmanlı Tarihi Bilgi Yarışması
- Osmanlıca Kelime Oyunu
- Osmo ABCs
- Osmo Coding Awbie
- Osmo Coding Duo
- Osmo Coding Jam
- Osmo Costume Party
- Osmo Counting Town
- Osmo Detective Agency
- Osmo Hot Wheels™ MindRacers
- Osmo in Space
- Osmo Kaleidoscope
- Osmo Lettertopia
- Osmo Masterpiece
- Osmo Math Buzz
- Osmo Math Wizard
- Osmo Monster
- Osmo Newton
- Osmo Numbers
- Osmo Numbers Cooking Chaos
- Osmo Numbers Classic
- Osmo Numbers Toybox
- Osmo Pizza Co.
- Osmo Shape Builder
- Osmo Squiggle Magic
- Osmo Stories
- Osmo Tangram
- Osmo Tangram Classic
- Osmo Words
- Osmo Words Chomp
- Osmo Words Classic
- Osmo Words Explorers
- Osmo World
- Osmos
- Osmos for iPad
- Osmosis Solitaire
- Osmosmerka: Solve Word Search Puzzles Using Serbian Latin and Cyrillic Alphabets
- Osolo
- OSSAN Eggs! mini -Spring Ver.-
- OSSAN Eggs! mini -Summer Ver.-
- OSSAN Eggs! mini -Winter Ver.-
- OsterGlück Gütersloh
- Ostinato
- Ostle
- Ostinato
- Ostle
- Ostrich Among Us
- Ostrov Kostrov
- Osushiya-san
- Axe Clicker
- OsXs
- OT App Lite
- OT Country Quiz
- Otano Princess!
- OtaQuiz
- OTEDAMA
- Othello - Mini
- Othello - Reversi Board Game
- Othello - The Official Game
- Othello - TSITGames
- Othello Crush
- Othello EndingTraining
- Black and white board games
- Othello Multiplayer
- Othello Quest - Online Othello
- Othello swap it.
- Othello3D
- Othelloda Ext
- OthelloPower
- Other
- Fairy Tales : Hidden Objects
- Other Words
- Otherworld Legends
- Otherworldly Zombies