- O Athletik Houston
- O Boto Cor de Rosa
- Sistema de Queima Automática
- O My Soul Christian Meditation
- O My Soul: Meditation & Sleep
- O Personal Digital
- O!FitJab
- O'care Body Composition App
- O'DIDE
- O'Dive
- O's NLF
- O'TOP
- O-Care Aqua Tool
- O-Studio
- Nuvola Dental Check
- O.R.S Hydration Calculator - Japan
- O.R.S. Hydration Calculator
- O.TIMER - Office TIMER(通用版)
- O1-275 ME
- O1-275 Pro
- O1-275-6FI
- O2 - Breathing exercises
- O2 Active AUS
- O2 Active AUS
- O2 Aspen & O2 Dallas
- O2 SKIN - Trị mụn chuẩn y khoa
- O2 SOS
- O2 Spa
- O2Fit - Diet & Calorie Counter
- O2Insight pro
- O2score
- O7 Therapy
- O9 Fitness
- O:RIN
- OA Studio TW - 街舞課程預約系統
- Oak - Meditation & Breathing
- Oak Haven Massage
- Oak Hill Gymnastics
- Oakdale Golf Club
- Oakland Teens
- Oakland University Rec Well
- Oakwood Athletic Club
- Oakwood Athletic Club App
- OAR Patches
- Oase Trainingsplanung
- Oasis
- Oasis city
- Oasis EVV
- Oasis Hot Yoga Studio
- OASIS LINK
- OASIS Tele
- OasisCloud
- Oathtrack Resident
- OAW Indoor Sports Complex
- OB App Suite
- OB Calc Oficial
- OB Patient Tracker 2
- Oband
- OBAT APPS: Cerdas Farmasi
- Obeat
- Obefis
- Oberberg FAIRsorgt
- Oberit - Reward Your Health
- Oberlausitzer Apotheken OHG
- Obezite&Diyabet Klinik Rehberi
- OBHealthy
- Obie: Fertility, cycle tracker