Shollu is an Islamic software that have main purpose to give warning, message or information to the user if prayer time is almost arrived in few minutes or is already arrived. So Moslem can prepare him self to get ready for pray. As Allah has already say in the Noble Quran, which meaning is:

“Verily, As-Salat ( the prayer) is enjoined on the believers on fixed hours” ( An-Nisa : 103)