David Šimák is software developer from Zlín, Czech Republic.

He started programming in JAVA since 2015 when he studies Technical Lyceum on high school in Zlín. Back then he using JAVA for creating mobile apps for Android OS. In 2017 he started two week internship in Elisoft s.r.o. where he is working today. In January 2019 he started learning JavaServer Faces (JSF) and started bringing some of his mobile apps to web. In December 2019 he started working on project Notes which is his first bigger project in ReactJS.

In his spare time he is hiking with his dog, learning new stuff, working on his own projects and sometimes creates websites in WordPress for his friends.

He is fan of Open Source Software especially of Linux. He using it as his daily driver for his computers and servers.

He currently develops mobile POS system EKONOM účtenka for ELISOFT s.r.o. and working on his own projects and sometimes work as freelancer. He is also open to new projects ideas or freelancing. Feel free to contact him.

Programming languages
Java, JavaServer Faces (JSF), Javascript, ReactJS

OSes and application server
Ubuntu, Ubuntu Server, Glassfish

Android Studio, IntelliJ Idea, VS Code, Netbeans

MongoDB, Room (an abstraction layer over SQLite)

Git, WordPress


My personal projects

Audio Recorder

Easily record your voice notes, business meetings, lectures or anything else

Barcode Generator

Simple online barcode generator​

Barcode Scanner

Simple barcode scanner for scanning QR codes and EAN codes


Simple and advanced mathematical functions


Chemical elements, compounds and periodic table


Upcoming project

Formula Solver

Physical and chemical calculation


Write your notes and checklists

Password Generator

Generate strong password online or on you android device

Pernetage Calculator

The fastest way to calculate discounts, tips, interest and other percentages​

Physical constants and formulas

Physics constants, formulas and more​

Sound Meter

Measure sound level around you

Random number generator

Simple app for generate random numbers

Text Converter

Encode or decode your text

Text Encryptor

App for encrypt text

Unit Converter

Simple unit converter for physics and chemistry

Other projects

EKONOM účtenka

Czech mobile cash register with EET support

Contact me