First of all, thanks for the great app! I use the shopping list on a daily basis.
My wife also has an Android phone so we enter items on our shopping list on two different devices. It would be great if we could synchronize these lists. Currently we use the send via e-mail option. This is not convenient as we end up switching between e-mail and the shopping list application. Also you cannot tick off items from the e-mail list.
I understand that synchronizing can be difficult to realize, but at least the option to have non existing items added to the list would be great. I think it is possible for applications to read incoming e-mail (when given permission). I can imagine having the menu option 'add to list on other device' which will send a specially encoded and tagged e-mail which will be picked up by the other device which scans all incoming messages.
All the best,