I use my old laptop as a media center and the biggest pet peeve I've had, has been the lack of a remote. Previously I'd used the VLC remote app but that didn't work with my VPN on until recently and required a network to be setup which isn't ideal. So I've been fiddling with wireless mice and keyboards. My motherboard recently shit the bed and while ordering new parts I noticed a "PC remote" on sale for 20 bucks. Basically this thing is like a Wii remote for a pc and it claimed to work on Linux as well.
It does and its a beauty. It's the same size as a small TV remote with only a few play/pause/power buttons on front but a full mini keyboard on back. The gyro to control the mouse pointer on it seems a bit fast at first but we will get used to it I imagine. Anyway I didn't know these existed so there's a heads up in case you didn't as well.
Nothing replaces a proper remote, not even a smartphone app--especially not a smartphone app.