PrimalityTest

Build your number adding the multiples of 1,2,3,4,5,6,7,8,9 or multiply for 10
so you can build your number and then check.

For example If I want text : 99499 I will type
+9 then x10 results 90
then +9 results 99 then x10 results 990 then +4 results 994 then x10
results 9940 then +9 results 9949 then x10 results 99490 then +9
results 99499. Leave in the feedback if you would prefer the standard input!
I will change everything in the next update!

Bug fixed with version next 1.0 :

+ ver. 1.1 fixed the the false positive bug "4 is prime" ;
+ ver.1.1.1 fixed the bug that crashed the app, added an upper bound for big integer;
+ added the button N/M that allow two different ways of input : N is normal like a standard calculator, M is incremental.
+ 1.2 and 1.3 minor bugs fixed
+ 1.4. overflow for big integer typed with normal mode fixed.
+ 1.5 fixed the crashing bug after "pressing any button after primality test" .

About icon: the picture of the face took from a statue,
that represents Eratosthenes.  
An ancient mathematician and philosopher
tha made the first procedure to determinate primes from 0 to 100.
(look the Sieve of Eratosthenes ).