This is the market listing for the app:
https://market.android.com/details?id=net.osmand.plus
The developer has a google codes site where you can download the nightly builds for free:
http://download.osmand.net/latest-night-build/
You have the choice of using numerous map sources. Vector maps are pretty small at 3 MB only. However, they are a bit slower to browse through and require more processing power (though on my Galaxy S 2 they seem just as fast as the Google caches). However, if you don't have Arabic support, then text will not render properly. So you can use the Google maps cached images in addition to the POI pack downloaded from the app itself. Another thing I noticed is that the app does not seem to distinguish between streets that are "b3ks el seir". So it always picks the best route (kind of like most Lebanese drivers :P ).