I tried a few different remotes and all of them connect over wifi. Is there a remove that allows you to control kodi from an android phone via bluetooth?
Which device are you trying to control (what is Kodi itself running on)?
The Unified Remote app has some capability for bluetooth for some devices, but not for others (for example the server side on a Pi doesn't support it, but on a PC it does iirc).
Unfortunately I was planning to use it on a Pi. Isn't there some sort of BT keyboard app or remote or something that would allow that?
I've never managed to find one (the closest I came was Unified Remote) - I'd be interested to discover one myself.
I found an app called true mouse that "works" but it needs root access. It's chunky but works if you are using a touch based device skin.