Pocket Islam is a freeware software by Smart Wireless for Windows Mobile 2003/5.0 owners. Here are some of the features of this great software-

Quran recitation (MP3).
Athan.
Arabic Holy Quran with tashkil (Othmanic Font to match the Paper Book).
Multiple Language Translation.
Hadith in Arabic (Sahih Bukhari, Muslim, Ibn Maja, etc..)
Tafseer Ibn Katheer
Prayer table.
Prayer schedule.
Qibla.
Moon data.
Hijri calendar.
Islamic events & Holidays.
Today Screen.

Pocket PC version- http://www.pocketislam.com/PocketIslamPPC.htm
Smartphone evrsion- http://www.pocketislam.com/PocketIslamSP.htm