SharpCap is described as 'easy-to-use and powerful astronomy camera capture tool. It can be used with dedicated astronomy cameras, webcams and USB frame grabbers' and is an app in the Education & Reference category. There are more than 10 alternatives to SharpCap for Windows, Mac, Linux, iPhone and Raspberry Pi. The best alternative is AllSkEye, which is free. Other great apps like SharpCap are FireCapture (Free), Nebulosity (Paid), AstroImager (Paid) and N.I.N.A. (Free, Open Source).
Qastrocam is a capture program to do astrophotography. It can control a telescope to do guiding with the images received from a V4L device. It can also control the extended features of a webcam modified to do long exposure (several seconds) captures.