Hello Andrew,
We use the BIAB app also at iPad and Android (I own both) as MusicReader for chords created in BIAB. In fact at both systems I can easily import thousands of files into the app from my dropbox.

Compared to iReal Pro, the app misses some very fundamental options. The most missing option is to be able to transpose per song rather then to transpose in the preference setting for all songs to adapt to the instrument key. Most of the time we always need to transpose all the time not only for adapting to an instrument key but also for the singer at any gig. So this should be a per song based setting and if this is too difficult it should be a transpose option directly available in the song.

Then the mgu files cannot be read by the app. They are converted while downloading from dropbox into .txt files. This prevents the ability to just import .mgu files into an Android directory. Or to attach a file to a pdf file and open it with the BIAB app which might gives you the opportunity to open the app directly and use it for transposing. So why this strange conversion into .txt?.

A second missing feature mainly in iPad is a paging. At iPad only 10x4 measures are present which is many times to less. Scrolling is no decent option. At Android 28x4 measures are visible at one page, which is mostly sufficient.

Solving a few of those shortcomings should already raise the value of these app a lot.
Rob

Musicians and music publishers are still wasting too much paper...come on men we live in the digitised age...Wake up!