Touché's companion app Lié is available for macOS 10.10 (and later) as well as for Windows 10.
There are no plans to offer Lié for older Windows versions like Windows 7 or Windows 8. It is particularly not recommended to try to flash the firmware of Touché (SE) with a Win7/8 device, since the USB architecture of these operating systems differ a lot from the one of Windows 10. Trying to do it nonetheless could (at least temporarily) brick your unit.
Please note: The basic functionality of Touché (SE) as a MIDI class compliant controller is not affected by the aforementioned compatibility restrictions.