[snikita]

My perspective on this question is that its convenience. If the app is something relatively simple, I just want to use it on the browser and not have to go through the steps of installing software that I probably will only use once. Also using a webapp is less dangerous than installing a program in the sense that it can't read your files, install malware, etc. I can relatively safely use an unknown webapp with confidence, but I would only install a program on my actual computer if I trust the author of it.