iDOS, also known as DOSPad. A DOS Emulator based on dosbox.
TeX Writer. TeX/LaTeX Editor and Compiler for iOS and Android.
Golden Ear. A Lossless Music Player for iOS.
Write Only. A minimalistic typewriter app for iOS.
LotsDots. Thinking by connecting dots.
HiveMemo. Spaced repetition flash card app for learning.
Twinkle Notes. Build your private knowledge base with end-to-end encrypted notes.
AEMULA, 80486 PC Emulator for ARM. Written from sratch.
TeX Equation. Typeset equation on iPad and paste into Pages/Keynote. For people working with formulas.