Simon Steinhage is an independent software developer based in Germany, designing, building, testing and shipping focused mobile apps under the name esues. His work includes native iOS development with SwiftUI and SwiftData, Android development with Kotlin, and German and English localisation. Hey Buddee is a personal friendship reminder tool with notes, birthdays and follow-ups, designed to keep information local with optional iCloud use. Kiwi des Schicksals provides fortune-cookie-style messages, while Chain Balls is a chain-reaction puzzle game. His projects start from a practical need or an interaction he wants to explore, with an emphasis on finishing small tools rather than building expansive platforms. The portfolio explains both the applications and the independent working process behind them.