The biggest problem over found with this is how unexpectedly easy it opens up the Android keyboard and obscures the keypad, but this is otherwise a fantastic tool. I've been searching for a no-Enter FOSS algebra calculator for literally years!
This looks like an awesome tool for anyone who loves having a powerful calculator at their fingertips! The calculate-as-you-type mode is perfect for quickly solving problems without losing your train of thought. Plus, those screenshots make it look super clean and easy to use.