- Knack - Tutoring Simplified
- Knackel
- Knatree
- Knaukey
- KNECHT - CuttingEdgeTechnology
- Kfans - KPop & KDrama Fandom
- Knit Camp
- Knnkt
- KnoCard
- Knock
- Knock Me Chat
- Knockk : Make friends & Outing
- KnockKnock.
- Knocknock: Tell Your Story
- KnokKnok: Vanishing Invites
- Knot Perfect: Social Media
- Know Me? - Quiz Your Friends
- Know your neighbour
- Know&Share
- Knowhere: Connect With Friends
- Knowledgeworker Share
- KnowledgeWorks Community
- Knowticed
- KNU PCPA 원우수첩
- Knubia
- Knuddels - chat and flirt
- KNVB Eén Tweetje
- Koala!
- Koalie
- KOC - Review là có tiền
- Kocaeli Barosu
- Kocaeli Platformu
- EasyCalls: Calling App
- Kodure - 子連れオフ会アプリ
- KoeTra
- KOG Go!
- KOGO by Mappls
- Kohi Sensei