Not for Windows. But for Unix-like OS via ConnectBot. Easy input Ctrl key. Each key is small, but enough keys. How to begin to use. 1. Install this app. 2. Open "Settings". 3. Tap " Language & input". # {. 4. Tap " Current Keyboard". 5. Tap "CHOOSE KEYBOARDS" or "SELECT MORE". # } or {. 4. Tap "Virtual keyboard". 5. Tap "Manage keyboards".