The app is totally safe for downloading. UNIAJC is the developer of STEP BY STEP CALCULATOR which can be found in the Educational category. People rated the tool 4.6 on Google Play.
The latest release was on Dec 3, 2014 and this application was downloaded and installed by over 1K users. You can get the setup package of STEP BY STEP CALCULATOR 1.0 free of charge and have a look at users' reviews on Droid Informer. The app runs on Android 2.2 and above.