I installed Ramble half an hour ago on my 2014 Moto G and it seems to be working as advertized! The only thing which confuses me is the empty list under the history tab. Is this a bug or is this feature not implemented yet?
I've implemented a UI hint to make this more obvious, which will be in the next version of RaMBLE.
Another thing I just realised is the number of new devices in the notification label. Let's say I put ramble in the background. After 10 minutes it tells me that there are n_1 new devices. I click on the notification in order to check them out. If I then put ramble in the background and it finds n_2 new devices then the notification says that there are now n_1 + n_2 new devices. I would expect that it says n_2 devices.
If you export the database you can pull some more interesting numbers out, e.g. http://www.contextis.com/resources/blog/bluetooth-le-increas...