Jan Čislinský

Jan Čislinský

Founder of Zvednout to? — the top-rated Czech call-blocking app. Side project since 2016, full-time since May 2026.

Zvednout to? app icon

Zvednout to?

The #1 Czech caller ID app

More at zvednoutto.cz — Zvednout to? caller ID app

Download on the
App Store
Screened calls in the app: an AI Bodyguard answers unknown callers and leaves a short Czech summary of who called and why.
New

AI Bodyguard

Answers your phone calls, finds out who is calling and why — in Czech — then sends you a summary.

Background

In mobile engineering since 2014. Spent 2019–2026 at JLL, growing from Lead iOS Engineer to Senior Manager, Software Engineering, and scaling mobile teams across continents. Earlier: Lead iOS at Etnetera, iOS Developer at Letsgood.com. VŠE graduate.

Press

Kvůli aplikaci na neznámá čísla vstával v pět ráno. Pak dal v práci výpověď a staví z ní velký byznys

CzechCrunch — Ondřej Holzman

Aug 2026

Projects

Zvednout to?

2016 – present

Caller ID, call blocking, and AI call screening in Czech, for iOS.

BetPivot

2019

Basketball bets recommendation app. Shut down — business model didn't pan out.

Siever

2017–2018

SMS scam filter. Never gained traction.

Vivio

2015

Safari ad blocker. Sold my stake to my co-founder.