I have been using the app for just over a week now, on a Samsung Galaxy Tab 2 7.0.
The only issue that has cropped up since Sunday is sharing my drives. When I choose a route and start navigating, selecting to share the drive directly from the list that pops up, caused the app to crash. I removed and reinstalled the app, as well as clearing my cache & data, and it still did this. What appears to work now is if I first touch the icon to share my drive with my contacts, THEN choose who I want to share a drive from there, and it seems to work fine. It do did so this morning. However, if I choose a contact directly from that first screen, then it crashes, but not if I go the long route (pun not intended), to share a drive with the same contact.
I tried to see if it was a setting, and from a clean install made changes step-by-step, and the only possible suspect I could get was when I changed from the default map colour scheme, and also when I added a Parking Icon accidentally, as doing this seemed to make the app unstable. However, as mentioned in the previous paragraph, as long as I first go into my contacts and share the drive from there, and not directly, all is well, regardless of parking icons or map colour scheme settings.
I searched for this issue on this forum, as well as via Google, and didn't seem to come up with anything, but at least it seems there is a workaround for the crashes.
Otherwise a great app, got a 4* rating from me on the Play store, just wish more people around me would use it, AND report traffic and other hazards. As with any GPS, it sometimes has some bizarre routing ideas, but can forgive Serena this oddity, as I think I am in love, lol!