GCC was in many reviews, podcasts and tests on different geocaching sites. The feedback was allways really good. The ratings at the market emphasize this. So, give GCC a try! :)

You will find the full feature list and changelog on:
http://gcc.eisbehr.de

Info:
The "GCC donate version" is exactly the same, like the free version. You just support the developer with a donation!

Functions:

ADFG(V)X (en-/decrypt)
Affine
Alpha Numeric
ASCII Converter
Astro
- Sun/Moon Rise/Set
- Easter Date
- Easter Years
- Seasons
- Shadow Calculator
Atbash
Bacon (en-/decode)
Base16, 32, 64, 85 (en-/decode)
Brainfuck/Ook
Caesar (en-/decrypt)
Colors:
- CMY, CMYK, HEX, HSL, HSV, RGB, YIQ, YUV, YCBCR
Coordinates
- Bearing
- Converter
- Distance
- Geohash
- Intersection Bearing
- Intersection Distance/Radius (two&three)
- Intersection Circle
- Intersection Lines
- Midpoint
- Projection
Cross Total
- A=1/Z=26
- A=26/Z=1
- interated
- alternating
- sum
- product
Deadfish (en-/decrypt)
DNA
e (Eulers number)
Enigma
Formula Solver
- own formulas and values
- many mathematical functions
Gade
GC Base 31 (en-/decode)
Hashes
- BKDR
- DEK
- DJB
- ELF
- FNV
- MD2
- MD4
- MD5
- PJW
- RIPEMD-128
- RIPEMD-160
- SDBM
- SHA-1 160, 254, 384, 512
- SHA-3 224, 254, 384, 512
- Tiger
- Whirlpool
- ...
Heatindex
Hint (en-/decode)
Kamasutra (en-/decrypt)
Kenny's Code (en-/decrypt)
Morse Code Translator
myGEOtools
- Alchemical Symbols
- Ancient Egyptian Numbers
- Antiker
- Arcadian
- Atbash / Caesar
- ATH-Code
- Bacon's cipher
- Baudot
- Blox
- Brahmi
- Chappe-Code (optical Telegraph)
- Cherokee
- Cirth
- Code-Sun (mRNA)
- Colorhoney
- ColorTokki
- Daedric
- Dagger
- Decabit
- Dragon Runes
- Color Codes
- Finger Alphabet
- Flag Alphabet
- Fonic
- Freemasons Code
- Futurama
- Glagolitic
- Glagolitic Numerals
- Gargish
- Genreich
- Greek Numerals
- Lucky Numbers
- Gnommish
- Hexahue
- Hieratic Numbers
- HVD
- Hylian
- Hymmnos
- Intergalactic Code
- Indian Numerals
- Japanese Numerals
- Klingon Language
- Krypton Language
- Magicode
- Marain
- Matoran
- Mathematics and Physics Constants
- Maya
- Maze
- Modern Hylian
- Moonalphabet
- Musical Notation System
- Ogam
- Periodic System
- Punisch
- Pipeline 3D
- Pixel Code
- Polybios Cipher
- POSTNET and PLANET
- Puzzle Code
- Reality
- Romulan
- Sarati
- Segment Displays
- Sexagesimal System
- Spintype Alphabet
- Sunúz
- Tenctonese
- Tom Tom
- Ulog
- Utopian Code
- Visitor
- Semaphore
- Yán-Koryáni
- Gypsy Signs
- Babylonian Numbers
- Barbier Alphabeth
- 8-Point Braille
- Deafblind
- Fakoo
- Sign Writing
- Greek Alphabet
- Lorm Alphabet
- Nießen Alphabet
- Quadoo
- Cyrillic
- Shutter Telegraph
- Enochian Alphabet
- Space Invaders
- Dancing Man Code
- Templar
- DTMF/MFV Signals
Numeric Systems
- Converter
- Base
- Table
- Negate Bases
- Floating Point Numbers
One Time Pad
Periodic System of Elements
Permutations
Phone Keys
- Phone Number
- Vanity Code
- Input Keys
Phi (Golden Ratio)
Pi (Π)
Playfair (en-/decrypt)
Polybios (en-/decrypt)
Prime Numbers
- Number
- Nearest
- Position
- Is Prim
- Prime Factors
Projectile
Rail Fence (en-/decrypt)
Resistor Color Code Calculator (4-Ring/5-Ring)
Reverse
Roman Numeral
- Translator
- Chronogram
ROT5,13,18,47
Rotation
RSA
- En-/Decrypt
- 'E' Check
- 'D', 'N', 'φ' Calculator
- Prime Number Check
Skytale (en-/decrypt)
Solitaire (en-/decrypt)
Substitution
Tap Code (en-/decrypt)
Tapir (en-/decrypt)
Vigenère
Windchill
Zuse Z22/CCIT2 (en-/decrypt)

Features:

- Four Themes
- Three Font Sizes
- Six Charsets
- Dynamic User-Interface
- English and german translation
- Fully integration of myGEOtools
- Complete offline usage
- No permissions on the device needed
- App 2 SD
- Tablet Ready
- Two Widgets
- Function Search