Stellar Scientific Calculator — Android App Sold on Flippa: Skeuomorphic scientific calculator with 641,000 installs + a paid version
Stellar (XLM) Profit Calculator - CryptoGround
Free Advanced Scientific Calculator - Expression Mode - Up To 100 Decimal for Student and Teacher, Operations for Basic Mathematics such as Addition, Subtraction, Division, Multiplication, and Modulus:Amazon.com:Appstore for Android