- OLive Streaming
- Oll Inklusiv
- OlliChat
- Ollo
- Ollo For Dating
- Olly
- Olove
- OLPH Chattanooga
- Oltner Fasnacht
- Olvid
- Olympia College
- Olympus App
- OM Plus
- We Are One Regional Meeting
- OMA Meetings and Events
- 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
- Omnity
- Omolink App
- OMOTENASHI - Live Video Chat
- Oméris et Moi
- On Air Fest
- On Air Messenger - Speech recognizer for sending messages!
- ON Dispatch
- On The Block - Local Services
- ON Dispatch
- On The Block - Local Services
- On the Spot Hangout App
- ON TIME CHAT
- On-Meet
- ON-计划打卡
- 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 Call Now Mobile
- One Chat -All in one Messenger
- One Chat All-in-One Messenger
- One Christian Love
- One Diary!