Predictable Android has the same device restrictions on phone as on tablet (Minimum 2GB RAM & running Android 5.0 or above), but some customers with compatible devices are experiencing crashes whilst they type.
This seems to be caused by the UK word prediction dictionary, and we will be fixing this issue for the next update. In the meantime, it can be remedied by going into settings > word prediction > dictionaries, then choosing US English. This will create some issues with the word prediction engine getting certain spellings incorrect for UK or Australian users, however it will learn new spellings and should -- with continues use -- start predicting the correct spelling after some time.