- Oliveira Monitoramento
- OLive Streaming
- Oll Inklusiv
- Oll3H: Business Contact Cards
- OlliChat
- Olly
- Olove
- OLPH Chattanooga
- Oltner Fasnacht
- Olvid
- Olympia College
- Olympus App
- OMA OMA
- Omada - Make Sport Social
- Omapost - stuur een kaartje
- Chat Pal-talk with new friends
- Omega Live Video Broadcast
- Omega Psi Phi On The Go
- OmeTV – Video Chat Alternative
- OMG Classified
- OMG Font Keyboard
- Hoop - Video Chat
- OMG俱乐部 -官方粉丝社区
- OMHC
- Omi - Date & Meet Friends
- Omijo
- Ommie
- Omni Chat
- OMNI Now
- Omnibook
- Omnichat
- Omolink App
- OMOTENASHI - Live Video Chat
- OMT
- Oméris et Moi
- On Air Fest
- On Air Messenger - Speech recognizer for sending messages!
- ON Dispatch
- On the Spot Hangout App
- ON TIME CHAT
- On the Spot Hangout App
- ON TIME CHAT
- On-Meet
- OnAire: Pause Your Moments
- Once Photos
- Onclass Messenger
- OnDaySix Christian Dating App
- Ondernemend Tilburg
- Onderwijs portalen
- OnDo: мессенджер с экосистемой
- One Another
- One Billiards AR Experience
- One Chat -All in one Messenger
- One Chat All-in-One Messenger
- One Christian Love
- One Connect - Copy Trade
- One Diary!
- One Heddon St
- One Hope Charity & Welfare