Unusual Keyboard Layout

Overall, this is a good iPhone calculator. The "landscape" calculator has a standard key layout, and it is fine.

However, the "portrait" calculator has a very unusual layout that can easily generate mistakes by the user. More specifically, the +/- key on the portrait calculator is located directly above the = key, which is NOT a standard position for that key. Normally, the + key is located directly above the = key. This is an issue that the developer really needs to address.

Maui Andy about Calculator!, v2.53