Hi, misspinky, you've got the right place (lots of mm users here), but wrong time (Saturday night, we're all out getting pi**ed!).
I'll tag a few other mm users to see if we can figure out an answer to this:
@Knikki ,
@porl69 ,
@Mel dCP
The Tomato app is very basic, few of us use it.
If you're on an android phone, I'd delete Tomato, and install xDrip+:
https://github.com/NightscoutFoundation/xDrip/releases
Yes, I know, it looks like a really dubious download from a site which you've never heard of, but it works, trust me on this.
Click the burger menu at top left, then Bluetooth Scan, wait a while, your mm should show up there, click it, and follow the instructions from there.
If you're on ios, hmm, well, that's had some ups and downs recently, I'll let Mel explain those...
When you get the mm working, it's well worthwhile.