Digital strategy and software from Istanbul.

We help businesses reach people and get paid, anywhere. We do marketing and strategy consulting, and we build web, mobile and desktop apps, with a focus on Bitcoin and Lightning payments.

About us

Twentyone Istanbul Dijital Pazarlama ve Stratejik Danışmanlık Limited Şirketi is a limited liability company registered in Istanbul, Türkiye, since January 2021. We work with local and international clients on digital marketing, strategy and technology. We also contribute to open-source Bitcoin software and build our own products on top of it.

Services

Digital marketing

Campaign planning, programmatic and social advertising, content and brand strategy.

Strategic consulting

Market research, positioning and go-to-market plans for digital products.

Software and apps

Web, mobile (iOS, Android) and desktop (macOS) applications, from prototype to release.

Bitcoin payments

Lightning and on-chain payment integration for online shops and local businesses.

Our apps

We are developing apps for iOS, Android and macOS. Each app will get its own page here with a description, support contact and privacy details. For support with any of our apps, write to kemal@twentyone.ist.

Lightning Address

Lightning Addresses for Blink non-custodial accounts. Claim you@twentyone.ist — coming soon.

Additional addresses for the same account (paid) — coming soon

Contact and company information

Legal name / Ticaret unvanı	Twentyone Istanbul Dijital Pazarlama ve Stratejik Danışmanlık Limited Şirketi
Email / E-posta	kemal@twentyone.ist
Registered in / Merkez	İstanbul, Türkiye
Tax office / Vergi dairesi	Beşiktaş Vergi Dairesi
Tax ID / Vergi kimlik no	8591203029
MERSIS no	0859120302900001
Trade registry / Ticaret sicil	İstanbul Ticaret Sicili Müdürlüğü, 286591-5