Turn an old cell phone into a wifi or bluetooth HTPC remote control

I'm thinking about using old computers and/or cell phones for home theater PC applications. Since having a remote control is kind of important in this house, we need something for screen sharing to navigate web pages for viewing and to select "full screen" to put the web's video on the full tv screen. Or perhaps a remote control program might be more useful? Also some of the old computers do not have bluetooth so wifi might be a handy option depending on what we use.

Do you have suggestions for screen sharing/remote control apps to use if I have Ubuntu Touch onto an old phone for this purpose? Or is another distro for this? Thanks!